Biochemistry Flashcards

Question

Which of the following is a monosaccharide? A. Sucrose B. Maltose C. Fructose D. Lactose E. Starch

Answer 1

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)

Answer 2

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.

Answer 3

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.

Answer 4

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.

Answer 5

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.

Answer 6

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)

Answer 7

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:

Answer 8

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:

Answer 9

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

Answer 10

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.

Answer 11

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.

Answer 12

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:

Answer 13

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).

Answer 14

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).

Answer 15

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.

Answer 16

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.

Answer 17

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.

Answer 18

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.

Answer 19

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.

Answer 20

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).

Answer 21

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.

Answer 22

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.

Answer 23

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.

Answer 24

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.

Answer 25

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.

Answer 26

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.

Answer 27

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.

Answer 28

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.

Answer 29

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.

Answer 30

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:

Answer 31

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:

Answer 32

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:

Answer 33

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.

Answer 34

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.

Answer 35

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.

Answer 36

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:

Answer 37

C. Ester linkage Note: fat=f*est* 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:

Answer 38

B. Waxes Note: monohydro*x*ylic(x=wa*x*es) 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.

Answer 39

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

Answer 40

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.

Answer 41

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:

Answer 42

B. Fatty acid carbon chains with double bonds and rings

Answer 43

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.

Answer 44

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.

Answer 45

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.

Answer 46

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.

Answer 47

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.

Answer 48

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.

Answer 49

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.

Answer 50

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.

Answer 51

D. Fat storage cells Note: think of A dip (they are storing their fatty chips)

Answer 52

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.

Answer 53

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.

Answer 54

C. Glycolipids contain a carbohydrate group Phospholipids can be described as molecules that contain two fatty acids, and a phosphate group bound to a glycerol backbone. Glycolipids contain a similar structure to phospholipids, however, instead have a carbohydrate group rather than a phosphate group.

Answer 55

C. Glycolipids contain a carbohydrate group Phospholipids can be described as molecules that contain two fatty acids, and a phosphate group bound to a glycerol backbone. Glycolipids contain a similar structure to phospholipids, however, instead have a carbohydrate group rather than a phosphate group.

Answer 56

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.

Answer 57

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.

Answer 58

C. Cholesterol is incorporated into the membrane To prevent cell membrane rigidity, one approach would be to incorporate cholesterol into the membrane. This will allow the membrane to become more fluid and prevent excess rigidity.

Answer 59

B. Unsaturated fatty acids At low temperatures, cell membranes begin to increase in rigidity. In order to avoid this, cholesterol and unsaturated fatty acids are incorporated within the membrane. This will allow for the prevention of an overly rigid membrane from forming, increasing fluidity.

Answer 60

B. Unsaturated fatty acids At low temperatures, cell membranes begin to increase in rigidity. In order to avoid this, cholesterol and unsaturated fatty acids are incorporated within the membrane. This will allow for the prevention of an overly rigid membrane from forming, increasing fluidity.

Answer 61

B. Saturated fatty acids At higher temperatures, the cell membrane becomes more fluid and flexible. In order to avoid the cell membrane from collapsing, saturated fatty acids and cholesterol are added to restrict movement. Saturated fatty acids accomplish this because their fatty acid tails are fully saturated with hydrogen atoms, this allows them to become straight, pack tightly, and thus decrease fluidity.

Answer 62

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.

Answer 63

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:

Answer 64

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:

Answer 65

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.

Answer 66

B. Storage protein Storage proteins serve as reserves of amino acids, and metal ions, which can be utilized for the maintenance and growth of organisms. Examples of storage proteins include ovalbumin in egg whites, casein in milk, and zein in corn seeds.

Answer 67

D. Transport protein [92%]

Answer 68

Transport protein Transport proteins function in moving materials within an organism. Hemoglobin is an example of transport protein as it carries oxygen into tissues.

Answer 69

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:

Answer 70

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:

Answer 71

D. Ribozyme Enzymes are described as unique molecules most of which (not all enzymes are proteins) are proteins that catalyze biochemical reactions. A ribozyme can be described as an RNA molecule, compared to other enzymes being known as protein molecules.

Answer 72

C. Coenzyme Cofactors can be described as non-protein molecules that assist enzymes. They include two classes: 1. If the cofactor is organic → Coenzyme (ex. Vitamins). 2. If the cofactor is inorganic → Metal ions (ex. Fe2+, Mg2+).

Answer 73

A. Coenzymes

Answer 74

E. Prosthetic group When a cofactor is covalently bound to an enzyme, the resulting molecule is known as a prosthetic group. Prosthetic groups are organic or inorganic non-protein molecules that are bound tightly to a protein to facilitate its function.

Answer 75

E. Prosthetic group When a cofactor is covalently bound to an enzyme, the resulting molecule is known as a prosthetic group. Prosthetic groups are organic or inorganic non-protein molecules that are bound tightly to a protein to facilitate its function.

Answer 76

B. Inorganic cofactors Cofactors can be described as non-protein molecules that assist enzymes. They include two classes: 1. If the cofactor is organic → Coenzyme (ex. Vitamins). 2. If the cofactor is inorganic → Metal ions (ex. Fe2+, Mg2+).

Answer 77

B. Inorganic cofactors Cofactors can be described as non-protein molecules that assist enzymes. They include two classes: 1. If the cofactor is organic → Coenzyme (ex. Vitamins). 2. If the cofactor is inorganic → Metal ions (ex. Fe2+, Mg2+).

Answer 78

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.

Answer 79

A. Simple protein Note: AI Bum In is so simple in the livo Albumin is classified as a simple protein, and it is the most abundant of the plasma proteins. It is a functional protein produced by the liver and is generally considered an example of a transport protein.

Answer 80

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:

Answer 81

E. Scleroprotein Note: scleo not conjugated yo 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. Options A-D are all examples of conjugated proteins, while Options E, is an example of a simple protein.

Answer 82

E. Scleroprotein Note: scleo not conjugated yo 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. Options A-D are all examples of conjugated proteins, while Options E, is an example of a simple protein.

Answer 83

B. Mucoprotein: protein + muscle cell Note: C*O*P (c=carb and p=protein) Mucoproteins are a class of conjugated proteins that contain simple proteins + non-protein components. Of the above choices, Option B is not labeled with its correct non-protein group. They are instead comprised of a protein + carbohydrate.

Answer 84

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.

Answer 85

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).

Answer 86

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:

Answer 87

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).

Answer 88

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).

Answer 89

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.

Answer 90

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:

Answer 91

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.

Answer 92

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:

Answer 93

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.

Answer 94

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.

Answer 95

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.

Answer 96

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.

Answer 97

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.

Answer 98

B. Protein denaturation leads to a loss of function When proteins are taken out of their ideal pH ranges, temperatures, or solvents, denaturation may occur. Protein denaturation can be described as a protein being reversed back to its primary structure. Furthermore, protein denaturation also implies that all of the information needed for a protein to assume its native state (its folded, functional form) is encoded in its primary structure. Since a protein’s function is dependent on its 3-dimensional structure, a denatured protein is non-functional.

Answer 99

C. Digestion is the complete elimination of the protein structure Protein digestion and protein denaturation are two separate concepts, that are often confused with each other. Protein digestion is involved with the elimination of all protein structures, including the primary structure. On the other hand, protein denaturation only reverses a protein back to its primary structure.

Answer 100

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.

Answer 101

A. Globular Note: why so global 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.

Answer 102

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.

Answer 103

Hydrophilic effect Globular proteins are water-soluble as a result of the non-covalent interactions between amino acid R groups in their tertiary structure. Hydrophobic amino acid side chains are buried, closely packed, in the interior of a globular protein, out of contact with water. However, hydrophilic amino acid side chains lie on the surface of the globular proteins exposed to the water. This hydrophilic effect between surface side chains and water contributes to a globular protein’s water solubility.

Answer 104

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.

Answer 105

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.

Answer 106

Three Cytosine and guanine (shown below) are known as nitrogenous bases. As a result of base pairing rules, cytosine can only base pair with guanine through the formation of three hydrogen bonds, while adenine can only pair with thymine through the formation of two hydrogen bonds.

Answer 107

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:

Answer 108

A. Adenine and thymine [6%] B. Adenine and uracil [0%] C. Adenine and guanine [89%] D. Cytosine and guanine [4%] E. Uracil and thymine [1%] Nitrogenous bases can be classified as either purines or pyrimidines. The purines include both adenine (A) and guanine (G), as shown below:

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Cytosine, uracil, thymine

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D. RNA is single stranded DNA and RNA are both known as nucleic acids/polymers of nucleotides, with nitrogenous bases that can vary based on whether it is DNA or RNA, as shown below. One difference between the two is that RNA is usually single-stranded.

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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:

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B. Phosphate groups As a result of the double-stranded, antiparallel, helical structure of DNA, a hydrophobic interior composed of nitrogenous bases is found. The negative charge of DNA is a result of the negative charge created from the phosphate groups. This allows DNA to be less susceptible to nucleophilic attack, increasing its stability.

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D. Number of rings Nitrogenous bases can be classified as either purines or pyrimidines, as shown below. The purines contain two rings, while the pyrimidines contain one ring.

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D. Nucleic acids

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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:

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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.

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B. Nucleoside diphosphate

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B. Cytosine

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A. Adenine

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C. Adenine

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B. DNA to RNA to protein

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E. All cells have walls All of the above option choices are true statements regarding the cell theory except Option E. In fact, Option E in itself is incorrect as not all cells contain cell walls.

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D. Cell According to the cell theory, the cell is the basic unit of structure, function, and organization in all organisms.

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B. All cells are not from pre-existing life All of the above option choices are true statements regarding the cell theory except Option B. The cell theory states that all cells do in fact come from pre-existing, living cells.

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D. Some cells arise due to random chemical reactions that occur spontaneously The cell theory explains that all cells come from pre-existing, living cells. This means Option D is an incorrect statement as they do not form due to random chemical reactions.

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B. RNA According to the RNA World Hypothesis, because RNA has the ability to store genetic information like DNA and catalyze chemical reactions in a similar way enzymes do, it is believed that RNA may have played a major role in the evolution of cellular life acting as a precursor to today’s current life.

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E. RNA participates in chemical reactions because of its instability

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A. Extra hydroxyl group

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B. The synthesis of molecules that requires energy

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A. Metabolism

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A. Anabolism

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B. Catabolism

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C. Concentration of both reactants and products The direction of chemical reactions can be affected by the concentrations of both the reactants and products. This can be further explained by the use of Le Chatelier’s Principles in the general chemistry section.

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zero When a reaction is in equilibrium, the rate of formation of reactants and products is equal which results in 0 net production. The example below is used to further explain this concept. Suppose a bridge is connecting two cities. (The bridge acting as the reaction itself), If the rate cars enter city A from city B is equal to the rate cars leave city A and enter city B, then the total number of cars on each end of the bridge going in each direction to each city should be equal.

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B. Catabolic

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A. Anabolic

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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.

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The breakdown of substances to produce energy

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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.

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D. Decreases activation energy

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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:

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B. Active site

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E. Substrate specific

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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.

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E. Substrate concentration at the half max velocity of the enzyme

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B. Active site and allosteric site

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D. Competitive inhibition

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B. Increase substrate concentration

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A. Km is raised

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E. Vmax is unchanged

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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.

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E. Pepsin When remembering the properties of enzymes, it may help to remember the properties of proteins because most (not all) enzymes are proteins. Hemoglobin may be tempting as it is commonly spoken about in this chapter as it has the ability to experience cooperativity, however, it is not an enzyme. Pepsin on the other hand is an enzyme responsible for protein digestion. Secreted in its inactive form pepsinogen, when activated, pepsin cleaves proteins via breaking peptide bonds in order to form smaller polypeptides

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D. Amino acids When remembering the properties of enzymes, it may help to remember the properties of proteins because most (not all) enzymes are proteins. Thus, enzymes/proteins also contain a unique combination of amino acid monomer units. This is what generates a specific environment, for a specific substrate to bind.

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B. Substrate can bind but reaction cannot be catalyzed

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A. Maximal velocity of an enzyme

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D. Uncompetitive inhibition Uncompetitive/anti-competitive inhibition occurs when an enzyme inhibitor binds only to the formed enzyme-substrate (ES) complex, preventing the formation of the product. Furthermore, uncompetitive inhibition also relates to Le Chatelier’s Principle from the general chemistry section. The equilibrium between ES complexes and ES-inhibitor complexes is disrupted by uncompetitive inhibition, as equilibrium favors the ESI. This results in ES complexes being depleted. The E + S → ES complex is subsequently shifted forward, so the enzyme’s apparent affinity for the substrate is raised, resulting in a lower Km.

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C. Km is unchanged

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E. Vmax is lowered

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B. Enzyme requires a small amount of substrate

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C. Heme-Hemoglobin Biological polymers are large molecules composed of many similar smaller molecules linked together in a chain-like fashion. The individual smaller molecules are called monomers. Proteins, carbohydrates or polysaccharides, nucleic acids, and lipids are the four major classes of biological macromolecules or polymers. Their respective monomers are amino acids, monosaccharides, nucleotides, and fatty acids with glycerol.