Biochemistry Flashcards
Glycosidic bonds are considered which of the following types of bonds?
covalent
Glycosidic bonds (shown below), also called glycosidic linkages, are considered covalent bonds formed via dehydration/condensation reactions occurring between two monosaccharides that join resulting in a loss of a water molecule for each covalent bond formed.
Covalent bonds are a type of bond where electrons are shared either between atoms of identical electronegativities equally (non-polar covalent) or with differing electronegativities (polar covalent) unequally.
Alpha helices and beta sheets are connected to their respective strands with which of the following bonds?
A. Hydrogen bonds
Alpha helices (shown below) and beta sheets are connected to their respective strands with the use of hydrogen bonds (bonds occurring when hydrogen is bonded to either fluorine, oxygen, or nitrogen).
Hydrogen bonding is the most prevalent interaction that occurs between carboxyl and amino groups of adjacent amino acids forming a polypeptide’s most common secondary structures, the alpha helix and beta sheets.
he bonds to create the tertiary structure of proteins can be associated with all of the following EXCEPT one. Which one is the EXCEPTION?
A. Vander der Waals
B. Ionic bonds
C. Hydrogen bonds
D. Metallic bonds
E. Disulfide bonds
D. Metallic bonds
The tertiary structure of a protein (shown below) represents the three-dimensional or overall shape of a protein caused by interactions of amino acid side chains, such as hydrophobic interactions, Vander der Waals interactions, ionic bonds, hydrogen bonds, and disulfide bridges.
Which of the following connects the amino acids of the primary structure of proteins?
covalent bonds
The primary structure of a protein (shown below) is comprised of a linear sequence of amino acids. These amino acids are linked via a peptide or covalent bond that attaches one AA’s carboxyl group and the other AA’s amino group together by undergoing dehydration reactions.
Which of the following compounds contain the strongest bonds?
A. NaCl
B. H2O
C. HNO3
D. CH4
E. HF
A. NaCl
Ionic bonds are formed between ions with opposite charges, as shown below. The electrons are not shared between the atoms as seen in covalent bonding, but rather are associated more with one ion than the other. Although hydrogen bonding may be seen in choices B, C, and E, it is not as strong as ionic bonding.
Which of the following lists the correct order from smallest to largest?
pam
Proton, atom, molecule
Protons are subatomic particles with a +1 electrical charge. Atoms, shown below, are known as the smallest unit of matter that still retains the properties of an element. They are comprised of protons, neutrons, and electrons. Finally, molecules form when two or more atoms join by chemical bonds.
A molecule is a group of
two or more atoms
Molecules are formed when two or more atoms join together by the use of chemical bonds (covalent bonds), as shown below:
Fluorine can strongly attract electrons because of its:
Electronegativity
The attraction an atom has for electrons is called its electronegativity. In other words, it is “how thirsty” an element is for electrons. The more electronegative an atom is (fluorine being the most electronegative element on the periodic table), the more it can pull electrons toward itself.
The bond in red is which type of bond?
A. Polar covalent bond
B. Non-polar covalent bond
C. Metallic bond
D. Ionic bond
E. Hydrogen bond
A. Polar covalent bond
Polar covalent bonds are chemical bonds formed between atoms that share electrons and have different electronegativities. On the other hand, hydrogen bonds are a type of bond formed when a Hydrogen (H) atom is bound to a highly electronegative atom (such as F, O, or N), causing the Hydrogen atom to take on a more positive charge. The more positively charged hydrogen atom is then attracted to another highly electronegative atom with at least one lone pair of electrons (typically F, O, or N).
You may be wondering why the bond in red is not a hydrogen bond. The hydrogen bond shown in the picture is polar covalent because it is a direct covalent bond between N and H atoms. A hydrogen bond would only be formed in this case if this ammonia molecule interacted with another ammonia molecule, as seen below:
Covalent bonds can have all the following properties EXCEPT one. Which one is the EXCEPTION?
A. Non-polar
B. Polar
C. Single bond
D. Double bond
E. Ionic bond
E. Ionic bond
Depending on the number of electrons being shared, covalent bonds can be single, double, or triple bonds, as shown below. Furthermore, non-polar covalent bonds involve the equal sharing of electrons between atoms whereas polar covalent bonds involve the unequal sharing of electrons.
Ionic bonds on the other hand are formed between ions with opposite charges. The electrons are not shared between the atoms as seen in covalent bonding, but rather are associated more with one ion than the other.
Which of the following bonds occurs due to the even sharing of electrons between two atoms with similar electronegativity?
A. Ionic bond
B. Covalent nonpolar bonds
C. Covalent polar bonds
D. Hydrogen bonds
E. Metallic bonds
B. Covalent nonpolar bonds
Covalent non-polar bonds are involved with the even or equal sharing of electrons between two atoms of similar or the same electronegativity. Different types of covalent bonds are shown below:
Which of the following bonds occur due to the uneven sharing of electrons between two atoms with different electronegativity?
A. Ionic bond
B. Covalent nonpolar bonds
C. Covalent polar bonds
D. Hydrogen bonds
E. Metallic bonds
C. Covalent polar bonds
Covalent polar bonds occur when an atom is bonded to another more electronegative atom preventing equal sharing of electrons between atoms, as shown below:
Which of the following would be the best biological solvent?
A. Water
B. Saline water
C. Triglycerides
D. Blood plasma
E. Sucrose
A. Water
Solvents can be described as a substance’s dissolving agent, while the thing that gets dissolved is described as the solute.
In the scenario of putting sugar in water, water acts as the solvent while sugar acts as the solute. The image below shows NaCl mixed with water. Note that hydrogen will encircle negatively charged ions, while oxygen will encircle positively charged ions.
Water is a very reliable solvent primarily due to the polarity it contains. However, it is important to note that, although the versatility of water as a solvent is vast, water is not a universal solvent. If it was, any container holding water, including our cells would be dissolved
Which of the following properties of water make it the best biological solvent?
A. High heat capacity
B. Dipoles of H2O
C. Surface tension
D. Adhesion
E. Cohesion
B. Dipoles of H2O
Water’s polarity caused by the dipoles of H2O allows it to function as a great solvent for polar substances and ions. This is due to polar molecules being more attracted to water i.e., being hydrophilic. Whereas non-polar molecules are repelled by water i.e., they are hydrophobic. This results in water making non-polar molecules aggregate together to avoid other water molecules, while polar substances dissolve further in the polar water. Shown below is an image of a water molecule:
The high heat of vaporization of water is explained by its:
A. High heat capacity
B. Dipoles of H2O
C. Surface tension
D. Adhesion
E. Cohesion
A. High heat capacity
The heat of vaporization of a substance can be described as the quantity of heat a liquid must absorb to transition from a liquid to a gaseous state. As a result of the same reason that water contains a high specific heat, i.e., because of its ability to form hydrogen bonds, it too contains a high heat of vaporization. This means, that due to requiring more heat to increase the temperature of water, it will also require more heat to vaporize the water.
If a large body of water is surrounded by a very high atmospheric temperature, which of the following will occur?
A. The temperature will be stable
B. The temperature will drop drastically
C. The temperature will increase drastically
D. The surface tension of the water will decrease drastically
E. The surface tension of the water will increase drastically
A. The temperature will be stable
The specific heat capacity of a substance is defined as the amount of heat that must be absorbed or lost for 1 g of that substance to change its temperature by 1 degree Celsius.
The ability of water to stabilize temperatures comes from its relatively high heat capacity. Because of the high specific heat of water relative to other materials — water contains the ability to minimize temperature changes of organisms living in large bodies of water and the environment.
Why is ice able to float in liquid water?
A. Ice is denser
B. Ice is less dense
C. Water is less dense
D. Water condenses
E. H-bonds become more fluid as ice
B. Ice is less dense
Unlike most substances you will encounter, water is one of the select few that are less dense as a solid than it is as a liquid due to the lattice structure of ice (shown below in (a)).
This means that while other substances may contract and become denser as they solidify, water instead expands due to the presence of extensive hydrogen bonding. This allows ice to float (shown below in (b)), as its density in the solid phase is less than water’s density when present in the liquid phase.
Which of the following occurs on a molecular level as water freezes?
A. Water condenses
B. H-bonds become more structured
C. H-bonds become more flexible
D. Crystalline structure disappears
E. The heat of vaporization changes
B. H-bonds become more structured
At low enough temperatures, water molecules begin to get locked into a crystal-like lattice structure (shown below in (a)) of hydrogen bonds, resulting in the formation of ice.
As the H-bonds become more structured, ice becomes less dense than liquid as water molecules get spaced further apart causing ice to float (shown below in (b)).
Which of the following properties of water allows insects to “walk” on its surface?
A. Heat of vaporization
B. Density
C. Cohesion and adhesion
D. High heat capacity
E. Covalent bonding
C. Cohesion and adhesion
Due to water’s polarity, it has the ability to be attracted to one another. This is what describes water’s ability to demonstrate its cohesive nature. Liquid water cohesion, in combination with adhesion, is responsible for water’s high surface tension. This allows small insects to walk on water, as shown below, because present at the air-water interface, there is extensive hydrogen bonding by the surface water molecules with the molecules below them
In the wintertime, a pond forms an ice surface. Which of the following best explains why?
A. Water is less dense than ice
B. The crystalline structure of ice is less dense than water
C. Cohesive properties of water allow ice to float
D. Adhesive properties of water allow ice to float
E. The high heat of vaporization prevents ice from ever melting
B. The crystalline structure of ice is less dense than water
During the wintertime, water molecules begin to get locked into a crystal-like lattice structure (shown below in (a)) of hydrogen bonds, resulting in the formation of ice. As the H-bonds become more structured, ice becomes less dense than liquid as water molecules get spaced further apart causing ice to float (shown below in (b)).
The ability for a pond to form an ice surface as a result of it having a lower density as a solid than as a liquid is a key factor in the suitability of the environments required for life.
Furthermore, over time, if ice began to sink, all the ponds, lakes and even the oceans would freeze, making life as we know it on Earth impossible.
In plants, the combination of the attraction between water molecules and the attraction between water molecules and the surface of vessels allows for the movement of water from the roots to the leaves against gravity. Which of the following terms best explains this phenomenon?
A. Crystal structure of H2O
B. High Heat Capacity
C. Capillary action
D. Osmosis
E. Dipoles of H2O
C. Capillary action
In this question, capillary action (as shown in the images below) can be defined as the ascension of water from the plant roots to leaves against the force of gravity due to the adhesive forces between water molecules and the plant cell walls and the cohesive forces between water molecules.
In plants, the attraction between water molecules and the xylem allows for the movement of water against gravity. Which of the following terms best explains why?
A. Adhesion
B. Cohesion
C. Surface tension
D. Osmosis
E. Dipoles of H2O
A. Adhesion
Adhesion is known as the clinging of one substance to another. Adhesion of water molecules to the xylem by the formation of hydrogen bonds helps counter the downward pull of gravity, as shown below:
The capillary action of water is related to both:
A. Surface tension and gravity
B. Surface tension and adhesion
C. Cohesion and adhesion
D. Cohesion and gravity
E. Osmosis and gravity
C. Cohesion and adhesion
As a result of water’s polar covalent bonds, water has the ability to form hydrogen bonds with itself and other neighboring polar molecules. Capillary action occurs as a result of both water’s cohesive nature i.e., the force that holds water molecules together, along with its adhesive nature i.e., the ability to “stick” to other polar molecules, as shown below:
Marine animals can live in large water bodies despite weather changes. Which of the following best explains why?
A. High heat capacity of water
B. Low heat capacity of water
C. Cohesion property of water
D. Adhesion property of water
E. Solvability of water
A. High heat capacity of water
Which of the following is a monosaccharide?
A. Sucrose
B. Maltose
C. Fructose
D. Lactose
E. Starch
C. Fructose
Note: you got mono from your GF
Monosaccharides are classified as single sugar molecules, known as simple sugars. Examples of monosaccharides include fructose and glucose, as shown below. Monomers such as these are the building blocks of more complex carbohydrates.
DAT Pro-Tip: “Monosaccharide” – Mono = single, sacchar = sugar)
Which of the following are used to link carbohydrates to each other?
A. Ester linkage
B. Peptide linkage
C. Glycosidic linkage
D. Ionic linkage
E. Metallic linkage
C. Glycosidic linkage
Carbohydrates such as monosaccharides undergo dehydration reactions where two monomers join via glycosidic linkages (shown below). Glycosidic linkages can be described as a covalent bond formed between two monosaccharides as a result of dehydration reactions. An example of this is when two molecules of glucose are linked together through glycosidic bonds to form the disaccharide maltose.
The key atom for all organic molecules is ___________.
carbon
Living matter is composed mostly of carbon, hydrogen, nitrogen, oxygen, along with some amounts of sulfur and phosphorus. Furthermore, the vast amount of biological diversity stems from carbon’s ability to form a wide number of molecules with varying number of bonds.
The key atom for all organic molecules is ___________.
carbon
Living matter is composed mostly of carbon, hydrogen, nitrogen, oxygen, along with some amounts of sulfur and phosphorus. Furthermore, the vast amount of biological diversity stems from carbon’s ability to form a wide number of molecules with varying number of bonds.
Which of the following contains the four major organic molecules?
A. Carbohydrates, salts, lipid, and acids
B. Carbohydrates, proteins, lipids, and nucleic acids
C. Waxes, lipids, DNA, and proteins
D. Waxes, carbohydrates, nucleic acids, and phospholipids
B. Carbohydrates, proteins, lipids, and nucleic acids
Carbohydrates, proteins, lipids, and nucleic acids are the four main classes of organic molecules. They go on to form various biological macromolecules that are described as large molecules necessary for life, built via smaller organic molecules.
Which of the following is a disaccharide?
A. Sucrose
B. Glucose
C. Fructose
D. Cellulose
E. Wax
A. Sucrose
SLM(SLmove)
A disaccharide is a sugar that consists of two monosaccharides that have joined via a glycosidic linkage (covalent bond) after undergoing a dehydration/condensation reaction. For example, the common disaccharide sucrose also known as table sugar, forms when monomers glucose and fructose undergo a dehydration reaction, joining together to form sucrose, as shown below:
suc=glu+fru (gf likes to suck)
Which of the following occurs to create a polymer from monomers?
A. Hydrolysis
B. Dehydration synthesis
C. Photosynthesis
D. Cellular respiration
E. Metabolism
B. Dehydration synthesis
The majority of macromolecules are formed via individual building blocks known as monomers. Monomers then combine together with the use of covalent bonds, ultimately, forming an even larger molecule known as a polymer.
When this reaction occurs, water is released as a byproduct. Dehydration/condensation reactions can be described as the method to put together single subunits while losing water in order to form larger molecules. A dehydration synthesis reaction is shown below:
Which of the following is required to break down a polymer into monomers?
A. Oxygen
B. Hydrogen
C. Water
D. Nitrogen
E. Carbon
C. Water
Polymers break down into individual monomers during a process known as hydrolysis. This is essentially the process of inserting a water molecule across a covalent bond in order to break it into two components, as shown below:
Which of the following defines a single sugar molecule?
A. Monosaccharide
B. Disaccharide
C. Polysaccharide
D. Lipid
E. Nucleic acid
A. Monosaccharide
It is important to remember that carbohydrates include both sugars and the polymers of sugars. However, of the carbohydrates, monosaccharides also known as simple sugars are the smallest units. Furthermore, monomers such as monosaccharides are used to build more complex molecules, as shown below:
Which of the following defines lactose?
A. Monosaccharide
B. Disaccharide
C. Polysaccharide
D. Lipid
E. Wax
B. Disaccharide
A disaccharide is a sugar that consists of two monosaccharides that have joined via a glycosidic linkage (covalent bond) after undergoing a dehydration/condensation reaction.
For example, the disaccharide lactose, also found naturally in milk, forms when monomer glucose is linked to galactose via undergoing a dehydration reaction, joining together to form lactose (shown below).
Not:
Lacking because panties glued to the gal
Carbohydrates are associated with all the following EXCEPT one. Which one is the EXCEPTION?
A. Starch
B. Glycogen
C. Cellulose
D. Chitin
E. Carotenoids
E. Carotenoids
Monosaccharides, disaccharides, and polysaccharides all fall under the category of carbohydrates. Starch, glycogen, cellulose, and chitin are all common examples of polysaccharides. Carotenoids, however, are considered accessory pigments present in the chloroplast of plants and some prokaryotes.
If a series of monosaccharides are bound together via dehydration synthesis, which of the following best defines this new molecule?
A. Monosaccharide
B. Disaccharide
C. Polysaccharide
D. Wax
E. Carotenoid
C. Polysaccharide
Polysaccharides are described as a long chain of monosaccharides or single sugar units joined by glycosidic bonds after undergoing dehydration/condensation reactions in which water molecules are also released. For example, starch, glycogen, cellulose (shown below), and chitin are common examples of polysaccharides.
Maltose is broken down into glucose molecules as water is added to the chemical bond. This breakdown mechanism is also known as _______________.
A. Hydrolysis
B. Dehydration synthesis
C. Metabolism
D. Anabolism
E. Photosynthesis
A. Hydrolysis
Disaccharides such as maltose, along with other polymers break down into individual monomers during a process known as hydrolysis. This is essentially the process of inserting a water molecule across a covalent bond to break it into two components (in this case being two molecules of glucose), as shown below:
Sucrose is made up of which two monosaccharides?
A. Glucose and glucose
B. Glucose and fructose
C. Glucose and galactose
D. Fructose and galactose
E. Glucose and lactose
B. Glucose and fructose
Note: because gf sucks dick
The common disaccharide sucrose, also known as table sugar, forms when monomers glucose and fructose undergo a dehydration reaction, joining together to form sucrose (shown below).
Lactose is made up of which two monosaccharides?
Glucose and galactose
Note: because your lacking since panties and glued to the gal
The disaccharide lactose, also found naturally in milk, forms when monomer glucose is linked to stereoisomer galactose via undergoing a dehydration reaction, joining together to form lactose (shown below).
Maltose is made up of which two monosaccharides?
glucose and glucose
Note: malt=melt (glucose melt with glucose)
The disaccharide maltose (shown below) is formed when two molecules of glucose are linked together through glycosidic bonds by undergoing dehydration/condensation reactions.
Which carbohydrate is used by plants to store energy?
A. Glycogen
B. Starch
C. Cellulose
D. Chitin
E. Carotenoid
B. Starch
Storage polysaccharides are utilized by both plants and animals to store sugars for later use. However, plants do this by storing starch in the form of amylose and amylopectin (shown below), which is described as a polymer of glucose.
An unknown cell is treated with iodine to test for the presence of starch. The test result is positive. The cell is, most likely, a ______________.
Plant cell
Storage polysaccharides are utilized by both plants and animals to store sugars for later use. However, plants do this by storing starch which is described as a polymer of glucose.
A common procedure used to test a cell for the presence of starch is known as the Iodine Test (shown below). A positive test result will indicate the presence of starch by forming a distinct blue-black colored complex.
Which carbohydrate is used by animals to store energy?
A. Starch
B. Chitin
C. Wax
D. Glycogen
E. Cellulose
D. Glycogen
Storage polysaccharides are utilized by both plants and animals to store sugars for later use. However, animals do this by storing glycogen.
Glycogen (shown below) is a polymer of glucose, it is similar in structure to amylopectin (branched form of plant starch), however, much more branching is present in glycogen.
Both starch and glycogen are:
A. Alpha glucose molecules
B. Beta glucose molecules
C. Structural molecules
D. Used by plants
E. Used by animals
A. Alpha glucose molecules
Note: SAG (girls with saggy tits are alpha)
Both starch and glycogen are alpha glucose molecules that are known as storage polysaccharides. Starch is the storage polysaccharide found in plants. It is composed of glucose monomers that are joined by either alpha 1- 4 or alpha 1- 6 glycosidic bonds. Note, that “1 – 4” and “1 – 6” refer to the specific number of the carbon. On the other hand, animals store the alpha glucose molecule glycogen, which can be described as the more highly branched equivalent of amylopectin (branched form of starch) in plants.
The structural integrity of plants is supported by which of the following polysaccharides?
A. Cellulose
B. Chitin
C. Starch
D. Glycogen
E. Carotenoid
A. Cellulose
The structural integrity of plants is supported by the polysaccharide cellulose (shown below). Cellulose is composed of glucose monomers that are linked via beta 1-4 glycosidic bonds.
They are held together in a parallel orientation, providing strong building blocks that plants can use to build tough cell walls (note, that cellulose is never branched).
Which of the following is stored in the human liver and used as an energy source?
A. Glucose
B. Starch
C. Glycogen
D. Fats
E. Adipose
C. Glycogen (l in glycogen is for liver)
Animals, including humans, use the storage polysaccharide glycogen (shown below) as an energy source. Vertebrates such as humans do this by storing glycogen, an alpha glucose molecule with extensive branching mainly in the liver and muscle cells.
When demand for sugar increases, glycogen in the body undergoes hydrolysis to release glucose to cells.
Which of the following is produced in plants, but cannot be digested by the human body?
A. Starch
B. Glycogen
C. Chitin
D. Cellulose
E. Carotenoids
D. Cellulose
The structural integrity of plants is supported by the polysaccharide cellulose (shown below). Cellulose is composed of glucose monomers that are linked via beta 1-4 glycosidic bonds. They are held together in a parallel orientation, providing strong building blocks that plants can use to build tough cell walls.
Enzymes in the human body do not have the ability to hydrolyze the beta linkages of cellulose. Thus, when cellulose enters our digestive tract, it simply passes through and gets eliminated.
Starch in plant cells is analogous to which of the following in animal cells?
A. Cellulose
B. Chitin
C. Glycogen
D. Wax
E. Carotenoids
C. Glycogen
Both starch and glycogen are alpha glucose molecules that are known as storage polysaccharides. Starch is the storage polysaccharide found in plants. It is composed of glucose monomers that are joined by either alpha 1- 4 or alpha 1- 6 glycosidic bonds. Note, that “1 – 4” and “1 – 6” refer to the specific number of the carbon.
On the other hand, animals store the alpha glucose molecule glycogen, which can be described as the more highly branched equivalent of amylopectin (branched form of starch) in plants.
Chitin in insect exoskeletons is analogous to which of the following in plant cells?
A. Cellulose
B. Glycogen
C. Starch
D. Alpha-glucose molecules
E. Carotenoids
A. Cellulose
Chitin (shown below) is a structural polysaccharide used by insects to build their exoskeletons and by many fungi to build their cell walls. This is analogous to plants using the structural polysaccharide cellulose as their cell walls building material.
Like cellulose, chitin also has beta linkages, however, the glucose monomer of chitin instead has a nitrogen-containing appendage.
The beta-glucose groups of chitin have which element connected to the sugar ring?
A. Carbon
B. Nitrogen
C. Phosphorous
D. Fluorine
E. Oxygen
B. Nitrogen
Chitin (shown below) is a structural polysaccharide used by insects to build their exoskeletons and by many fungi to build their cell walls. This is analogous to plants using the structural polysaccharide cellulose as their cell walls building material.
Like cellulose, chitin also has beta linkages, however, the glucose monomer of chitin instead has a nitrogen-containing appendage.
Chitin is used in both insect exoskeletons and in which of the following?
A. Fungal cells
B. Plant cells
C. Animal cells
D. Skin cells
E. Epithelial cells
A. Fungal cells
Chitin (shown below) is a structural polysaccharide, containing beta linkages used by insects to build their exoskeletons and by many fungi to build their cell walls.
Chitin is similar in structure to cellulose; however, the glucose monomer of chitin instead has a nitrogen-containing appendage.
Both cellulose and chitin are:
A. Alpha glucose molecules
B. Beta glucose molecules
C. Structural isomers
D. Used by plants
E. Used by animals
B. Beta glucose molecules
Note: CC close to b than a so it is beta
Both the structural polysaccharides, cellulose and chitin are classified as beta glucose molecules. However, it is important to note they are not identical, the glucose monomer of chitin instead has a nitrogen-containing appendage.
Lipids can be associated with all the following EXCEPT one. Which one is the EXCEPTION?
A. Energy storage
B. Hydrophilic molecules
C. Structural component of membranes
D. Endocrine signaling
E. Insulation
B. Hydrophilic molecules
Of the classes of biological molecules, lipids (shown below) are considered the only ones that are not known as true polymers. However, they are grouped together due to all lipids sharing a common trait; they are hydrophobic and mix very poorly with water because they contain many non-polar covalent bonds.
If a lipid is made up of three fatty acids and a glycerol backbone, which of the following must the molecule be?
A. Phospholipid
B. Steroid
C. Wax
D. Cholesterol
E. Triglyceride
E. Triglyceride
Although phospholipids, steroids, waxes, and cholesterol are all important classes of lipids, they are formed through other means. The lipid class that contains the triglycerides (another name for fat) is formed when three fatty acid molecules are joined to a glycerol backbone by the use of an ester linkage, as shown below.
DAT Pro-Tip: Fats can be called “Triacylglycerols” or “Triglycerides” due to their chemical structure.
The structure of saturated triglycerides can be associated with all the following EXCEPT one. Which one is the EXCEPTION?
A. Absence of double bonds
B. Straight chains
C. Loosely packed
D. Harmful to health
E. Lipid molecule
C. Loosely packed
The terms “saturated” vs. “unsaturated” regarding triglycerides are commonly seen. These terms are specifically referring to the fatty acid’s hydrocarbon chain. If there is an absence of double bonds, then as many hydrogen atoms can bind to the hydrocarbon chain as possible. This would describe a saturated fatty acid.
The absence of double bonds prevents kinks from forming as commonly seen in unsaturated fatty acids, thus, saturated fatty acids can pack in straight, tight chains, as shown below:
Which of the following best describes why saturated triglycerides are harmful to human health?
A. Stack loosely
B. Stack densely
C. Many double bonds
D. Kinks in their chains
E. Cis or trans fatty acids
B. Stack densely
When triglycerides contain no double bonds on their hydrocarbon structure, they are known as “saturated triglycerides”. Note, that they are considered “saturated” because it’s not possible to add any more hydrogens to the fatty acid carbon structure.
This allows saturated triglycerides such as butter to pack tightly/stack densely, also causing them to be solid at room temperature. Furthermore, due to the explained reasons, they also contribute to the formation of plaque in the arteries. Triacylglycerol is shown below:
Unsaturated triglycerides contain which of the following?
A. No double bonds
B. Straight chains
C. Kinked chains
D. Dense packaging
E. Monosaccharides
C. Kinked chains
When a triglyceride contains double bonds within its structure, it is known as an “unsaturated triglyceride”. The presence of a double bond allows for the indication of cis/trans configuration.
If the hydrogen atoms are on opposite planes across the double bond, it is described as being in a trans configuration.
On the other hand, if the hydrogens are on the same plane, it will be considered a cis unsaturated triglyceride. The “cis” double bond present, creates a “kink”, preventing the fatty acids from having straight chains, or stacking densely, as shown below:
Phospholipids are most similar in structure to __________.
A. Triacylglycerols
B. Steroids
C. ATP
D. Waxes
E. Carotenoids
A. Triacylglycerols
Phospholipids (shown below)are considered one of the major plasma membrane components of a cell that comprises its outermost layers. Similar to fats, they contain fatty acid chains attached to a glycerol backbone. However, phospholipids are bound to two fatty acids and a glycerol backbone compared to being attached to three fatty acids and a glycerol backbone as seen in triacylglycerols.
If a lipid is made up of two fatty acids and a phosphate group bound to a glycerol backbone, which of the following must the molecule be?
A. Triglyceride
B. Triacylglycerols
C. Phospholipid
D. Steroid
E. Cholesterol
C. Phospholipid
Phospholipids (shown below) can be described as molecules that contain two fatty acids and a phosphate group bound to a glycerol backbone.
Phospholipids differ when compared to triglycerides. Fats such as triglycerides are composed of three fatty acid tails attached to a glycerol backbone.
Phospholipids can self-assemble at the plasma membrane because of their:
A. Hydrophilic properties
B. Hydrophobic properties
C. Amphipathic properties
D. Saturated fatty acid
E. Unsaturated fatty acid
C. Amphipathic properties
Phospholipids (shown below), which consist of two fatty acids and a phosphate group being bound to a glycerol backbone are known as amphipathic molecules. Amphipathic describes a molecule with both hydrophobic and hydrophilic properties.
The phosphate head of a phospholipid is polar, hydrophilic, and negatively charged. While the fatty acid chains are non-polar, hydrophobic, and uncharged.
This is what describes phospholipid’s ability to self-assemble, as hydrophobic regions namely the fatty acid chains will aggregate together avoiding water, while phosphate groups face outward due to being hydrophilic.
Steroids are made up of which of the following rings?
A. Four six-membered rings
B. Four five-membered rings
C. Three six-membered rings and one five-membered ring
D. Three five-membered rings and one six-membered ring
E. Two fatty acids and a phosphate group
C. Three six-membered rings and one five-membered ring
Note: 36 15
Steroids such as sex hormones, cholesterol, and corticosteroids, are characterized as lipids consisting of a carbon skeleton comprised of four fused rings – three six-membered rings and one five-membered ring, as shown below:
Which of the following are used to link fatty acids to each other?
A. Glycosidic linkage
B. Peptide linkage
C. Ester linkage
D. Phosphodiester linkage
E. Metallic linkage
C. Ester linkage
Note: fat=fest or think fat people have low esteem
Fatty acids, such as the ones found in triglycerides (another name for fat) are formed when three fatty acid molecules are joined to a glycerol backbone by the use of an ester linkage. This can be described as a bond formed between a carboxyl and a hydroxyl group. Triacylglycerol is shown as below:
Fatty acid esters and monohydroxylic alcohols make which of the following?
A. Phospholipids
B. Waxes
C. Steroids
D. Sex hormones
E. Carotenoids
B. Waxes
Note: monohydroxylic(x=waxes)
Due to waxes being classified as lipids, they are hydrophobic in nature. Because of this, waxes have the ability to prevent water from sticking onto a surface of an organism. They are formed when long fatty acid chains undergo a process known as esterification where they become long-chain alcohols. Waxes can be found covering some plant leaf surfaces along with being present on some aquatic birds’ feathers.
Which of the following is similar to carbohydrates in that they can store energy?
A. DNA
B. Nucleic acids
C. Proteins
D. Lipids
E. Sex hormones
D. Lipids
Like carbohydrates, lipids also perform various functions within a cell. One, that is similar to carbohydrates, lipids function in, is storing energy within a cell. They do this by storing fat, as a means of long-term energy
Cholesterol is considered to be which of the following?
A. Phospholipid
B. Triglycerides
C. Carotenoid
D. Wax
E. Steroid
E. Steroid
Cholesterol (shown below) is the most common class of steroids, and it is primarily synthesized in the liver. Like other steroids, it contains a four fused carbon ring structure and acts as a precursor to various important steroid molecules such as estrogen, testosterone, and progesterone. Furthermore, it also acts as the precursor to Vitamin D and bile salts.
If a lipid has a four-ring structure, then it is most likely a:
A. Steroid
B. Wax
C. Carotenoid
D. Triglyceride
E. Phospholipid
A. Steroid
Steroids, unlike other lipids such as waxes, carotenoids, triglycerides, and phospholipids do not resemble each other. They are grouped together and classified as lipids due to their hydrophobic nature and their poor ability to mix with water if at all. It is important to note that, all steroids consist of four fused carbon ring structures, as shown below:
Which of the following best describes the structure of a carotenoid?
A. Esters of fatty acids and monohydroxy alcohols
B. Fatty acid carbon chains with double bonds and rings
C. Four ring structures
D. Three fatty acid chains attached to a glycerol backbone
E. Two fatty acids and a phosphate group
B. Fatty acid carbon chains with double bonds and rings
Carotenoids are used as:
A. Protective coating for animals
B. Animal membrane components
C. Pigments for plants and animals
D. Sex hormones
E. Structural molecules for fungal cells
C. Pigments for plants and animals
Carotenoids are a class of lipids that are used as pigments which produces colors in plants and animals. Their structure involves a fatty acid carbon chain with conjugated double bonds and a six-membered carbon ring at each end. Subgroups of carotenoids include carotenes, such as beta-carotene (shown below), and xanthophylls.
Which components make up the amphipathic property of phospholipids?
A. The polar glycerol backbone and hydrophobic chains
B. The polar phosphate head and a nonpolar hydrocarbon tail
C. The polar OH groups in the glycerol backbone and a nonpolar chain
D. The molecular geometry of phospholipids contributes to their amphipathic property
E. The nonpolar chains interact with polar OH groups
B. The polar phosphate head and a nonpolar hydrocarbon tail
Phospholipids (shown below), which consist of two fatty acids and a phosphate group being bound to a glycerol backbone are known as being amphiphilic molecules. This means both hydrophobic and hydrophilic portions of the molecule are present.
The phosphate head of a phospholipid is polar, hydrophilic, and negatively charged. While the fatty acid chains are non-polar, hydrophobic, and uncharged.
Lipid function can be associated with all the following EXCEPT one. Which one is the EXCEPTION?
A. Major role in the endocrine function of both male and female reproductive organs
B. Acts as a secondary form of energy storage
C. Aids in human body temperature regulation
D. Maintains the structural integrity and membrane fluidity of cell membranes
E. Creates a waterproof barrier of the human skin
E. Creates a waterproof barrier of the human skin
Lipids can be associated with all of the above option choices except Option E. Keratinocytes, a skin cell located in the epidermis produces a protein named keratin. This is what is responsible for the waterproofing of the human skin.
Which of the following lipids is associated with detrimental health effects and plaque formation in human blood vessels?
A. Unsaturated triglycerides
B. Saturated triglycerides
C. Waxes
D. Carotenoids
E. Steroids
B. Saturated triglycerides
hen triglycerides contain no double bonds, they are known as “saturated triglycerides”, as shown below. Note, that they are considered “saturated” because it’s not possible to add any more hydrogens to the fatty acid carbon structure.
This allows saturated triglycerides such as butter to pack tightly/stack densely, also causing them to be solid at room temperature. Furthermore, due to the explained reasons, they also contribute to the formation of plaque in the arteries such as human blood vessels.
Chlorosis is the yellowing of plant leaves and a loss of pigment. Which of the following could the plant leaves be deficient in?
A. Hemoglobin
B. Carotenoids
C. Wax
D. Cholesterol
E. Phospholipids
B. Carotenoids
Carotenoids, such as beta-carotene (shown below), are a class of lipids that are used as pigments which produce colors in plants and animals. Thus, a deficiency may result in a loss of plant pigmentation. Their structure involves a fatty acid carbon chain with conjugated double bonds and a six-membered carbon ring at each end.
Which of the following lipid derivatives is used as a protective coating for some organisms?
A. Phospholipids
B. Carotenoids
C. Wax
D. Steroids
E. Cholesterol
C. Wax
Due to waxes being classified as lipids, they are hydrophobic in nature. Because of this, waxes have the ability to prevent water from sticking onto a surface of an organism. They are formed when long fatty acid chains undergo a process known as esterification where they become long-chain alcohols. Waxes can be found covering some plant leaf surfaces along with being present on some aquatic birds’ feathers.
Which of the following lipid derivatives is used as a protective coating for some organisms?
A. Phospholipids
B. Carotenoids
C. Wax
D. Steroids
E. Cholesterol
C. Wax
Due to waxes being classified as lipids, they are hydrophobic in nature. Because of this, waxes have the ability to prevent water from sticking onto a surface of an organism. They are formed when long fatty acid chains undergo a process known as esterification where they become long-chain alcohols. Waxes can be found covering some plant leaf surfaces along with being present on some aquatic birds’ feathers.
Which of the following are used to create the structure of hemoglobin?
A. Waxes
B. Xanthophylls
C. Porphyrins
D. Carotenoids
E. Steroids
C. Porphyrins
Porphyrins (tetrapyrroles) can be described as a class of lipids that are comprised of four joined pyrrole rings that are often complex with a metal ion.
In the case of hemoglobin, the “heme” component is responsible for binding to oxygen, as shown below. It consists of a metal ion in the form of iron and a porphyrin ring that binds to the “globin” molecules.
Adipocytes are:
A. White fat cells
B. Brown fat cells
C. Located in the epidermis
D. Fat storage cells
E. Fat transporters
D. Fat storage cells
Note: think of A dip (they are storing their fatty chips)
Which of the following is a difference between white and brown fat cells?
A. White fat cells have a substantial amount of cytoplasm
B. White fat cells are not adipocytes
C. Brown cells have a minuscule amount of cytoplasm
D. Brown cells have a substantial amount of mitochondria
E. Brown cells have a carbohydrate group
D. Brown cells have a substantial amount of mitochondria
Note: In brown cells, mitochondria thrive,
Their numbers high, you can’t deny.
Adipocytes (shown below) are a class of lipids and are classified as being specialized fat storage cells. There are two types which include brown fat cells and white fat cells.
Brown fat cells contain considerable cytoplasm, lipid droplets scattered throughout, and lots of mitochondria. On the other hand, white fat cells are composed primarily of triglycerides with a small layer of cytoplasm around it.
Adipocytes can be categorized as:
A. Glycolipids and white fat cells
B. Glycolipids and lipoproteins
C. Glycolipids and brown fat cells
D. White and brown fat cells
E. Brown fat cells and lipoproteins
D. White and brown fat cells
Note: you can dip white and brown chips
Adipocytes (shown below) are a class of lipids and are classified as specialized fat storage cells. There are two categories which include white fat cells and brown fat cells.
Biochemistry - Question Bank #78
Difficulty Level:
Which of the following are used to transport lipid throughout the blood?
A. Phospholipids
B. Glycolipids
C. Brown fat cells
D. Adipocytes
E. Lipoproteins
E. Lipoproteins
Lipoproteins (shown below) are used to transport lipids throughout the blood due to lipids hydrophobic nature causing them to be insoluble. Lipoproteins contain lipid cores surrounded by phospholipids and apolipoproteins.
The cores of lipoproteins are coated by which of the following molecules?
A. Brown and fat cells
B. Glycolipids and brown fat cells
C. Phospholipids and apolipoproteins
D. Phospholipids and sterols
E. Phospholipids and waxes
C. Phospholipids and apolipoproteins
Lipoproteins (shown below) are used to transport lipids throughout the blood due to lipids hydrophobic nature causing them to be insoluble. Lipoproteins contain lipid cores surrounded by phospholipids and apolipoproteins.
Due to a malfunction in a lipid derivative, lipids are unable to be transported through the bloodstream in a patient. Which of the following is most likely the root of the problem?
A. White fat cells
B. Brown fat cells
C. Adipocytes
D. Lipoproteins
E. Glycolipids
D. Lipoproteins
Lipoproteins (shown below) are used to transport lipids throughout the blood due to lipids hydrophobic nature causing them to be insoluble. Lipoproteins contain lipid cores surrounded by phospholipids and apolipoproteins.
Which of the following is the monomer of proteins?
A. Nucleic acids
B. Amino acids
C. Monosaccharides
D. Fatty acids
E. Glycerols
B. Amino acids
The monomers of proteins are known as amino acids. Each amino acid contains an amino group, carboxyl group, carbon, and R group, as shown below:
Which of the following are the structural components of amino acids?
A. Secondary Messenger
B. DNA, fatty acid, and glycerol backbone
C. Amino group, DNA, carbon, and R group
D. Amino group, carboxyl group, carbon, and R group
E. Amino group, carboxyl group, RNA, and R group
D. Amino group, carboxyl group, carbon, and R group
An amino acid’s structural components include a central asymmetric carbon to which a hydrogen atom, carboxyl group, amino group, and an R group are attached to, as shown below:
The component of amino acids that make them distinctive from each other is the ______________.
A. Amine group
B. Carboxyl group
C. R group
D. Peptide bond number
E. Position of the amine group
C. R group
Note: its like a pirate that makes their accent distinctive
The R group (shown below) of an amino acid specifies which class of amino acids it belongs to. The unique characteristics/variability of these groups causes an amino acid to form various types of bonds and interactions including but not limited to: ionic, hydrogen, disulfide, and nonpolar and polar interactions.
Hemoglobin is classified as which of the following proteins?
A. Storage protein [3%]
B. Structural protein [3%]
C. Membrane protein [1%]
D. Transport protein [92%]
E. Catalyst protein [1%]
D. Transport protein [92%]
Enzymes can:
A. Only catalyze from the forward direction
B. Only catalyze from the reverse direction
C. Change the spontaneity of the reaction
D. Catalyze in the forward and reverse direction
E. Alter the equilibrium concentrations
D. Catalyze in the forward and reverse direction
Enzymes can be described as unique molecules most of which (not all enzymes are proteins) are proteins that catalyze biochemical reactions. They function in lowering the activation energies of chemical reactions in both the forward and reverse directions, as shown below:
Proteins that function to catalyze chemical reactions are called which of the following?
A. Ribosomes
B. Apoprotein
C. Enzymes
D. Cofactors
E. Prosthetic groups
C. Enzymes
Enzymes can be described as unique molecules most of which (not all enzymes are proteins) are proteins that catalyze biochemical reactions. They function in lowering the activation energies of chemical reactions in both the forward and reverse directions, as shown below:
Vitamins that aid enzymes are considered to be:
A. Coenzymes
B. Ribozymes
C. Lipoproteins
D. Apoenzymes
E. Apoproteins
A. Coenzymes
Which of the following protein classifications does a chain of amino acids fall under?
A. Simple
B. Conjugated
C. Tertiary
D. Lipoprotein
E. Secondary
A. Simple
Note: think of that chain is simple why that guy flexin with his rental
Of the various categories of protein classifications, simple proteins are formed entirely of amino acids. A protein’s primary structure (shown below) is also described as a sequence of amino acids connected by peptide bonds.
Which of the following best describes a conjugated protein?
A. Protein and lipid
B. Protein and non-protein
C. Protein and DNA
D. Protein and saccharide
E. Protein and cofactor
B. Protein and non-protein
Unlike simple proteins, which contain only amino acids, conjugated proteins are comprised of simple proteins combined with some other non-protein component usually being named its prosthetic group. An example of a conjugated protein includes the metalloprotein hemoglobin containing the “heme” prosthetic group, as shown below:
Which protein structure is defined by amino acids bound with peptide bonds?
A. Primary structure
B. Secondary structure
C. Tertiary structure
D. Quaternary structure
E. Conjugated
A. Primary structure
The primary structure of a protein (shown below) is comprised of a linear sequence of amino acids. These amino acids are linked via a peptide or covalent bond that attaches one AA’s carboxyl group and the other AA’s amino group together by undergoing dehydration reactions.
Which of the following best describes the development of the secondary protein structure?
A. Amino acids bound with peptide bonds
B. Non-covalent interactions of R groups
C. Aggregation of separate peptide chains
D. Hydrogen bonding between amino and carboxyl groups of amino acids
E. Protein and nonprotein interactions
D. Hydrogen bonding between amino and carboxyl groups of amino acids
Note: It is the second time that AB is high
The secondary structure of a protein (shown below in the first image) results from intermolecular interactions between atoms of a polypeptide backbone (not the R-group). These interactions include things such as hydrogen bonding (bonds occurring when hydrogen is bonded to either fluorine, oxygen, or nitrogen) as the most prevalent interaction that occurs between carboxyl and amino groups of adjacent amino acids forming a polypeptide most common secondary structures, the alpha helix, and beta sheets (shown below in the second image).
Alpha helices and beta sheets are present in which protein structure?
A. Primary structure
B. Secondary structure
C. Tertiary structure
D. Quaternary structure
E. Globular structure
B. Secondary structure
The secondary structure of a protein results from intermolecular interactions between atoms of a polypeptide backbone (not the R group). These interactions include things such as hydrogen bonding (bonds occurring when hydrogen is bonded to either fluorine, oxygen, or nitrogen) as the most prevalent interaction that occurs between carboxyl and amino groups of adjacent amino acids forming a polypeptide most common secondary structures, the alpha helix and beta sheets, as shown below:
Tertiary protein structures form due to the:
A. Non-covalent interactions between R groups of amino acids
B. Protein chain summation
C. Amino acids joining via peptide bonds
D. Beta sheets and alpha helices interactions
E. Hydrogen bonding between amino and carboxyl groups of amino acids
A. Non-covalent interactions between R groups of amino acids
Note: think of turt (halo) non co (your driving and shooting)
The tertiary structure of a protein (shown below) represents the three-dimensional or overall shape of a protein caused by the non-covalent interactions of amino acid side chains, such as hydrophobic interactions, Van der Waals interactions, ionic bonds, hydrogen bonds, and disulfide bridges (an exception to non-covalent).
Tertiary structures of proteins can contain all of the following interaction types EXCEPT one. Which one is the EXCEPTION?
A. Hydrogen bonds
B. Hydrophilic interactions
C. Disulfide bonds
D. Ionic bonds
E. Van der Waal forces
B. Hydrophilic interactions
Note: Turt dont like water or else ciao
The tertiary structure of a protein (shown below) represents the three-dimensional or overall shape of a protein caused by the non-covalent interactions of amino acid side chains, such as hydrophobic interactions, Vander der Waals interactions, ionic bonds, hydrogen bonds, and disulfide bridges (an exception to non-covalent).
Disulfide bonds are strong covalent bonds between which of the following?
A. Glycines
B. Serines
C. Cysteines
D. Tyrosines
E. Histidines
C. Cysteines
Disulfide bonds are strong covalent bonds formed by interactions between the amino acid cysteine side chains, ultimately forming disulfide linkages (S – S bonds). These disulfide linkages are the only covalent bond formed during the process of protein folding.
A protein is considered to be in a quaternary structure if which of the following occurs?
A. Peptide chains come together
B. Non-covalent interactions occur
C. Alpha helices develop
D. Amino acids come together
E. Proteins bind to nonproteins
A. Peptide chains come together
Note: think of PC comes together to form a square which is 4 sides, hence quaternary structure
Some proteins are formed when separate peptide chain subunits interact and come together creating the quaternary structure of a protein, as shown below:
Which of the following is common among all proteins?
A. Conjugation to a non-protein
B. Primary structure
C. Secondary structure
D. Tertiary structure
E. Quaternary structure
B. Primary structure
Need to start with something uk
The primary structure of a protein (shown below) is composed of a sequence of amino acids that make up the entirety of the polypeptide chain. All proteins contain an amino acid sequence; thus, all proteins will have a primary structure.
Which of the following lists protein structures from most to least common as they appear in protein?
A. Secondary, primary, tertiary, quaternary
B. Primary, tertiary, secondary, quaternary
C. Quaternary, tertiary, secondary, primary
D. Primary, secondary, tertiary, quaternary
E. Primary, tertiary, secondary, quaternary
D. Primary, secondary, tertiary, quaternary
Protein structure, from most common to least common goes in the order of the words “primary, secondary, tertiary, quaternary”, as shown below:
Which of the following best describes a globular protein?
A. Water-insoluble
B. Secondary structure dominant
C. Structural protein
D. Diverse functionality
E. Membrane protein
D. Diverse functionality
Globular proteins (shown below) can be described as somewhat water-soluble, mostly dominated by tertiary structure, and contain a diverse range of functionality including enzymatic, hormonal, inter/intracellular storage and transport, osmotic regulation, and immune responses.
Which of the following DNA base pairs requires the most energy to break?
A. Adenine-Thymine
B. Guanine-Thymine
C. Guanine-Cytosine
D. Adenine-Uracil
E. Cytosine-Thymine
C. Guanine-Cytosine
The four bases in DNA are adenine (A), cytosine (C), guanine (G), and thymine (T). These bases form specific pairs (A with T, and G with C), as shown below. The guanine and cytosine base pairing forms 3 hydrogen bonds and adenine and thymine form only 2 hydrogen bonds. Thus, the G-C base pair has the strongest interactions and requires the most amount of energy to break.
Which of the following is the most dominant protein structure for globular proteins?
A. Conjugated
B. Tertiary
C. Primary
D. Secondary
E. Quaternary
B. Tertiary
Note: G has 3 lines that connects the G
Globular proteins can be described as somewhat water-soluble, mostly dominated by tertiary structure, and contain a diverse range of functionality including enzymatic, hormonal, inter/intracellular storage and transport, osmotic regulation, and immune responses.
Which protein is most favorable to provide structural integrity to the cellular membrane?
A. Chromoprotein
B. Fibrous
C. Globular
D. Membrane
E. Lipoprotein
B. Fibrous
Note: Fibe tv provides structural integrity
Fibrous proteins (shown below) such as collagen or keratin can be described as being water-insoluble, and are mostly dominated by secondary structure. Furthermore, they are made of long polymers that function to provide strength that is used to maintain the structural integrity of cellular and matrix structures.
To pump water through the cell membrane, which of the following proteins should be used?
A. Lipoprotein
B. Mucoprotein
C. Membrane protein
D. Fibrous protein
E. Nucleoprotein
C. Membrane protein
Membrane proteins can be described as proteins that are bound to, or in association with the cellular membrane of a cell or organelle, as shown below. These include proteins that function as membrane pumps (ex: sodium-potassium pump), channels, or receptors.
The greatest determinant of a protein’s function is:
A. pH
B. R group
C. Prosthetic group
D. Cofactors
E. Structure
E. Structure
The greatest determinant of a protein’s function is described as a protein’s structure (shown below). This is because its structure is dependent on its amino acid sequence and interactions present in both the amino acid side chains and the polypeptide backbone. Thus, if a protein begins to lose part of its structure, it may not be able to function as properly as it once did, if at all.
Which of the following best describes the receptors that line the cell surface?
A. Glycolipids
B. Vesicles
C. Histones
D. Membrane proteins
E. Glycocalyx
D. Membrane proteins
Membrane proteins can be described as proteins that are bound to, or in association with the cellular membrane of a cell or organelle, as shown below. These include proteins that function as membrane pumps (ex: sodium-potassium pump), channels, or receptors.
All of the following are nitrogenous bases associated with DNA EXCEPT one. Which one is the EXCEPTION?
Uracil
Adenine and guanine are known as purines (shown below) and are nitrogenous bases that are associated with both DNA and RNA. Thymine, cytosine and uracil are all classified as pyrimidines (shown below), however, only cytosine is seen in both DNA and RNA. Thymine is associated with DNA; however, uracil is only associated with RNA.
Adenine and thymine pair with how many hydrogen bonds?
A. One
B. Two
C. Three
D. Four
E. Five
B. Two
Adenine and thymine (shown below) are known as nitrogenous bases. As a result of base pairing rules, adenine can only pair with thymine through the formation of two hydrogen bonds, while cytosine can only base pair with guanine through the formation of three hydrogen bonds.
Which of the following is replaced by uracil in the nitrogenous bases of RNA?
Thymine
Adenine and guanine are known as purines (shown below) and are nitrogenous bases that are associated with both DNA and RNA. Thymine, cytosine, and uracil are all classified as pyrimidines (shown below), however, only cytosine is seen in both DNA and RNA. Thymine on the other hand is associated with DNA, however, is replaced by uracil in RNA, as shown below:
Purines and pyrimidines have how many rings respectively?
2, 1
DNA and RNA contain which sugars respectively?
A. Ribose sugar, ribose sugar
B. Deoxyribose sugar, deoxyribose sugar
C. Deoxyribose sugar, ribose sugar
D. Ribose sugar, deoxyribose sugar
E. Ribose sugar, uracil
C. Deoxyribose sugar, ribose sugar
There are two types of pentose sugars found in nucleotides, these include deoxyribose (in DNA), and ribose (in RNA). Both are similar in structure, however, ribose has an OH at the 2` position, as shown below:
Nucleotides are made up of a:
A. Nitrogenous base, a five-carbon sugar, and a phosphate group
B. Nitrogenous base, a four-carbon sugar, and a phosphate group
C. Nitrogenous base, a carboxyl group, and an amino acid
D. Nitrogenous base, an amine group, and an amino acid
E. Nitrogenous base, a carboxyl group, and an R group
A. Nitrogenous base, a five-carbon sugar, and a phosphate group
Nucleotides are described as the monomers that make up nucleic acids and consists of a nitrogenous base, a five-carbon sugar, and a phosphate group, as shown below:
To form a nucleotide from a nucleoside, which of the following must be added?
A. Amino acid
B. Phosphate group
C. Five-carbon sugar
D. R group
E. Carboxyl group
B. Phosphate group
Nucleotides are described as the monomers that make up nucleic acids and consist of a nitrogenous base, a five-carbon sugar, and a phosphate group. However, nucleotides should not be confused with nucleosides (shown below), which consist of a sugar and a nitrogenous base. Thus, to form a nucleotide from a nucleoside, you must add a phosphate group.
Which of the following do Guanine pair with?
A. Adenine
B. Cytosine
C. Cysteine
D. Uracil
E. Thymine
B. Cytosine
Which of the following do Uracil pair with?
A. Adenine
B. Thymine
C. Guanine
D. Cysteine
E. Cytosine
A. Adenine
Which of the following do Thymine pair with?
A. Guanine
B. Aldosterone
C. Adenine
D. Cysteine
E. Cytosine
C. Adenine
The central dogma follows which pathway of information transfer?
A. DNA to protein to RNA
B. DNA to RNA to protein
C. Protein to RNA to DNA
D. Protein to DNA to RNA
E. RNA to DNA to protein
B. DNA to RNA to protein
RNA is different than DNA functionally in that:
A. RNA does not store genetic information
B. DNA can catalyze chemical reactions
C. DNA is less stable due to the extra hydroxyl group
D. DNA is capable of self-replication
E. RNA participates in chemical reactions because of its instability
E. RNA participates in chemical reactions because of its instability
RNA is considered to be less stable than DNA because it has a(n):
A. Extra hydroxyl group
B. Uracil nitrogenous base
C. Thymine nitrogenous base
D. Phosphate group
E. Deoxyribose sugar
A. Extra hydroxyl group
Which of the following best describes anabolism?
A. The breakdown of substances to produce energy
B. The synthesis of molecules that requires energy
C. The group of reactions that produce energy
D. The sum of all digestive processes
E. The enzyme activity in a cell
B. The synthesis of molecules that requires energy
All of the chemical processes in the human body that sustain life is known as _______________.
A. Metabolism
B. Photosynthesis
C. Cellular respiration
D. Glycolysis
E. Beta oxidation
A. Metabolism
Gluconeogenesis is an example of:
A. Anabolism
B. Catabolism
C. Photosynthesis
D. Digestion
E. Cellular respiration
A. Anabolism
Glycogenolysis is an example of:
A. Anabolism
B. Catabolism
C. Cellular respiration
D. Beta oxidation
E. Photosynthesis
B. Catabolism
Which reaction breaks a protein down to amino acids?
A. Anabolic
B. Catabolic
B. Catabolic
Which reaction creates a polysaccharide from glucose?
A. Anabolic
B. Catabolic
A. Anabolic
Which of the following describes metabolism?
A. A group of catabolic reactions that breakdown molecules for energy
B. A group of anabolic reactions that store energy
C. A group of anabolic and catabolic reactions that produce energy
D. A group of reactions that catalyze the catabolic reactions for energy production
E. A group of reactions that accelerate the nutrient intake after digestion to produce energy
C. A group of anabolic and catabolic reactions that produce energy
Metabolism can be described as the combination of anabolic and catabolic reactions occurring in the body that produces energy, as shown below. Although anabolic reactions require energy to create and store larger molecules when the body requires energy at a later point — these larger molecules are then broken down in order to release energy.
Which of the following best describes catabolism?
A. The breakdown of substances to produce energy
B. The synthesis of molecules that store energy
C. The breakdown of substances that requires energy
D. The sum of all digestive processes
E. The enzyme activity in a cell
The breakdown of substances to produce energy
In the body, which of the following experiences cooperativity?
A. Hemoglobin
B. Chloroplast
C. Mitochondria
D. Lysosomes
E. Osteoblast
A. Hemoglobin
Cooperativity can be described as a phenomenon that occurs where an enzyme becomes more receptive to additional substrate molecules after one substrate molecule binds to the active site.
Although hemoglobin (shown below) is not an enzyme, it is commonly used as an example of biological cooperativity. Hemoglobin is a quaternary protein with 4 subunits that each contain an active site for the binding of a single oxygen. When the first oxygen binds, the next active site becomes more receptive to binding another oxygen.
Which of the following best describes the ability of enzymes to catalyze reactions?
A. Increases activation energy
B. Increases total energy release
C. Decreases total energy release
D. Decreases activation energy
E. Decreasing rate of reaction
D. Decreases activation energy
If a Km value of an enzyme is elevated, then the:
A. Substrate does not bind to the enzyme well
B. Substrate binds to the enzyme well
C. Vmax is reached with a miniscule amount of Km
D. Enzyme is experiencing noncompetitive inhibition
E. Enzyme does not require a lot of substrates
A. Substrate does not bind to the enzyme well
The “Km” value is known as the Michaelis constant and represents the substrate concentration at which the rate of reaction is half of the max velocity of the enzyme or Vmax. In a way, this value inversely represents binding affinity. This means that an elevated Km will result in worse substrate binding, while a lowered Km would result in better substrate binding, as shown below:
Which of the following does a substrate bind to in an enzyme with induced fit?
A. Allosteric site
B. Active site
C. Competitive inhibitor
D. Non-competitive inhibitor
E. Anti-competitive inhibitor
B. Active site
red
Which of the following is true concerning enzymes?
A. pH insensitive
B. Temperature insensitive
C. Altered by reaction
D. Catalyze forward direction only
E. Substrate specific
E. Substrate specific
Which of the following is a frequently used source of activation energy for biological chemical reactions?
A. Glucose
B. Sucrose
C. GTP
D. ATP
E. ADP
D. ATP
Activation energy can be described as the “hill” a reaction must climb in order to move forward, as shown below. This is where the role of ATP comes into play.
ATP is a common source of activation energy, and the compound stores its potential energy in the form of chemical energy. New ATP is formed via phosphorylation, ADP and phosphate come together using energy from an energy-rich molecule like glucose.
Which of the following best describes Km?
A. Enzyme concentration at the max velocity of the enzyme
B. Enzyme concentration at the half max velocity of the enzyme
C. Product concentration at the max velocity of the enzyme
D. Product concentration at the half max velocity of the enzyme
E. Substrate concentration at the half max velocity of the enzyme
E. Substrate concentration at the half max velocity of the enzyme
If an enzyme is an allosteric enzyme, which sites will it have?
A. Active site only
B. Active site and allosteric site
C. Allosteric site only
D. Active site and allosteric activator site
E. Active site and allosteric inhibitor site
B. Active site and allosteric site
A drug can inhibit a substrate by mimicking its structure and binding to its enzyme’s active site. Which of the following is occurring?
A. Non-competitive inhibition
B. Uncompetitive inhibition
C. Anti-competitive inhibition
D. Competitive inhibition
E. Allosteric inhibition
D. Competitive inhibition
In order to counteract competitive inhibition, which of the following can be done?
A. Increase enzyme concentration
B. Increase substrate concentration
C. Increase inhibitor concentration
D. Decrease substrate concentration
E. Decrease enzyme concentration
B. Increase substrate concentration
During competitive inhibition of an enzyme, which of the following occurs?
A. Km is raised
B. Km is lowered
C. Vmax is raised
D. Vmax is lowered
E. Both Km and Vmax are raised
A. Km is raised
During competitive inhibition of an enzyme, which of the following occurs?
A. Km is lowered
B. Reaction rate is unchanged
C. Vmax is lowered
D. Vmax is raised
E. Vmax is unchanged
E. Vmax is unchanged
A substance binds to an allosteric site of an enzyme, preventing the needed chemical reaction from going through completion. Which of the following is occurring to the enzyme?
A. Competitive inhibition
B. Non-competitive inhibition
C. Uncompetitive inhibition
D. Anti-competitive inhibition
E. Active site substrate binding
B. Non-competitive inhibition
When non-competitive inhibition (shown below) occurs, a non-competitive inhibitor molecule binds to the allosteric site of the enzyme, preventing the substrate from binding to the active site and thus, decreasing the maximal rate or Vmax of the reaction.
If binding affinity is high, then Km is:
A. Low
B. High
A. Low
Vmax is the:
A. Maximal velocity of an enzyme
B. Maximal substrate binding to an enzyme
C. Maximal reactant production of an enzyme
D. Maximal Km value at any given velocity
E. Maximal velocity of a substrate
A. Maximal velocity of an enzyme
Difficulty Level:
In non-competitive inhibition, which of the following is occurring?
A. Km is lowered
B. Km is raised
C. Km is unchanged
D. Vmax is unchanged
E. Vmax is raised
C. Km is unchanged
In non-competitive inhibition, which of the following is occurring?
A. Km is lowered
B. Km is raised
C. Vmax is unchanged
D. Vmax is raised
E. Vmax is lowered
E. Vmax is lowered
If the Km value of an enzyme is small, which of the following best represents what is occurring?
A. Enzyme requires a lot of substrates
B. Enzyme requires a small amount of substrate
C. Enzyme is experiencing competitive inhibition
D. Enzyme is experiencing noncompetitive inhibition
E. Substrate cannot bind to the enzyme well
B. Enzyme requires a small amount of substrate
