2.1-2.5 quiz prep Flashcards
How many covalent bonds can carbon form?
four, with bonds between carbon atoms being particularly stable (catenation)
What does the number of covalent bonds for carbon allow it to do?
Allows for a wide variety of different shapes and structures. (Rings, chains, branches can be created)
What are the different types of carbon compounds?
carbohydrates, lipids, proteins, nucleic acids
What are the four macromolecules that make up the molecules that are necessary for life?
carbohydrates, lipids, proteins, nucleic acids
Carbohydrates are…..
Most abundant organic compound found in nature, composed of C, H, and O atoms, functions as a source of energy. An important recognition molecule
Lipids are…..
non polar and hydrophobic molecules that include fats, oils, and cholesterol. Are a major component of cel membranes, long term energy storage molecule
Nucleic acids are…..
Genetic material of all cells and determines the inherited features of an organism. DNA & RNA
Proteins are…..
composed of C, H, O and N atoms (some may include S), Major regulatory molecules involved in catalysis, and may also function as structural molecules
Metabolism is…..
A web of all enzyme catalyzed reactions in a cell or organism.
Where does metabolism occur?
cytoplasm
What are examples of metabolism?
photosynthesis, cell respiration, and protein synthesis
What are the two components of metabolism?
anabolism and catabolism
Anabolism is….
Reactions that convert simple molecules into larger, more complex molecules.
Why does anabolism occur?
to re-form the larger, biochemically important molecules.
What are examples of anabolism?
protein synthesis and DNA synthesis, photosynthesis and synthesis of complex carbs
What is the opposite of anabolism?
catabolism
What is catabolism?
Reactions that break down complex molecules (food) into smaller, simpler molecular forms.
What can catabolism be achieved by?
hydrolysis
What is hydrolysis?
Adding water to break molecules down, it requires a molecule of water as a reactant.
What gets released during catabolism?
energy
What are examples of catabolism?
Digestion and cellular respiration
Are water molecules polar or non polar?
polar
What forms between water molecules?
hydrogen bonds
What are polar molecules?
having a pair of equal and opposite charges
What is the medium of life?
water
What is cohesion?
Attraction between molecules of the same substance
How does a hydrogen bond form?
When the positive end of one water molecule attracts the negative end of another, a hydrogen bond occurs. This allows for water to form droplets, have a surface tension, and move as a “column” in plant vascular tissue.
What is surface tension?
the strong cohesive forces of water molecules at the surface, which forms a layer or film that makes it difficult to move an object over the surface.
What is adhesion?
the attraction of unlike molecules, such as water and cellulose.
What does cohesion and adhesion do when water moves up through a capillary tube?
both cohesion and adhesion are at work. Cohesion pulls the water up the tube; adhesion keeps the water from falling down
What has thermal properties?
water
What are the thermal properties of water?
High specific heat capacity, High latent heat of vaporization, High boiling point
Why can water dissolve a lot of substances?
Because of its polarity. A vast majority of molecules found in and out of cells are also polar molecules.
What are the solvent properties of water?
Can be used to dissolve ionic and polar compounds, because of the polar nature of water
Due to water’s excellent solvent properties, what does that make it?
water is an excellent transport medium.
Hydrophobic
water hating
Hydrophilic
water loving
What do hydrophobic molecules include?
lipids and hydrocarbons, which are non-polar and aren’t soluble in water.
What are monosaccharides?
simple sugars that combine to make larger molecules (glucose, fructose, galactose)
What are disaccharides?
two monosaccharides joined together. Examples include maltose, lactose, and sucrose.
What is maltose?
combination of two glucose molecules.
What is lactose?
combination of glucose and galactose
What is sucrose?
combination of glucose and fructose.
What are polysaccharides?
chains of monosaccharides that are used in energy storage. Examples include starch, glycogen, and cellulose.
How are disaccharides and polysaccharides constructed?
in condensation reactions that remove water from the process.
What must happen for condensation reactions that create disaccharides and polysaccharides to occur?
molecules must collide in a particular orientation, at a particular speed, and depends on the identity of the reactant.
What is used to increase the chances that biochemical reactions take place?
enzymes
What are enzymes?
Proteins that speed up chemical reactions
What are amino acids?
The building blocks of proteins. 20 different kinds.
What do amino acids contain?
contains an amino group and a carboxyl group attached to a central carbon atom with a terminal hydrogen and a variable group denoted as “R.”
What do ribosome connect?
connect amino acids to make proteins.
What does the process that produces a peptide bond create?
a protein and a water molecule
What do peptide bonds do to make a dipeptide?
combines two amino acids
What are most proteins?
polypeptides
When polypeptides are synthesized at ribosomes under the control of DNA, what reaction takes place?
a condensation reaction
What is the amino acid sequence determined by?
DNA
What causes the different forms and structures of proteins?
their variety of functions
What happens when proteins are folded?
hydrogen bonds stabilize the molecule
How many levels of protein structure are there?
4; primary, secondary, tertiary, quaternary
What are polypeptides?
single amino acid chains with their own primary structures.
What is a polypeptide considered as if it can carry out its function?
a protein
Are proteins polypeptides?
proteins are polypeptides
Are all polypeptides proteins?
no
What is a genome?
A specific DNA sequence that is unique to an individual
What are proteins denatured by?
urea, extreme pH, extreme temperature, extreme salt concentrations (tonicity)
What is the set of proteins synthesized by cell called?
proteome of the cell
What is the sequence and number of amino acids determined by?
the cell’s genetic code
.
.
What are enzymes?
Enzymes are long chains of aminos that have taken a 3D shape. These shapes are called globular.
What are enzymes built to match?
a specific substrate
Substrate
reactant of an enzyme-catalyzed reaction
What is urea?
a waste product of nitrogen metabolism and is eliminated by the kidneys in mammals.
What is the name of the area of the enzyme that directly correlates to the substrate?
active site
What must happen for biological reaction to take place?
substrates must collide with the active site in a particular orientation and with a minimum rate of motion so the reaction can take place.
Are enzymes used in a reaction?
no, ezymes lower the energy required for the reaction, but they themselves are not used up in the reaction.
What factors affect enzyme-catalyzed reactions?
temperature, pH, concentration of the substrate, and immobilized enzymes
How does temperature affect enzyme -catalyzed reactions?
Increasing temperature increases the speed at which molecules move and thus collide.
How does pH affect enzyme -catalyzed reactions?
The pH can change how fast enzyme-catalyzed reactions occur.
How does concentration of the substrate affect enzyme -catalyzed reactions?
Increasing concentration increases reaction rates because of the number of collisions increase.
How does immobilized enzymes of the substrate affect enzyme -catalyzed reactions?
allows one to re-use the enzyme for an extended period of time and enables easier separation of the catalyst from the product.
catalyst
substance that speeds up the rate of a chemical reaction
Catalase
An enzyme produced in all cells to decompose hydrogen peroxide
what can produce urea?
can be produced by both living and unloving
What is vitalism?
a theory has since been disproven with the discovery that organic molecules can be artificially synthesised
What reaction occurs when a dipeptide is formed from amino acids?
condensation
What is an organic compound found in both plant and animal cells?
Pyruvate
Which of the following substances are organic?
I. Phospholipids
II. Oxygen
III. Carbon dioxide
I only
How many molecules of water are required to completely hydrolysea polypeptide made up of 23 amino acids?
22
An enzyme is a biological catalyst, define the term catalyst. (1 mark)
substance that speeds up the rate of a chemical reaction
Anabolism is an important process in cells. Outline the process of anabolism with reference to an example. (6 marks)
-Synthesis of complex molecules from simpler molecules
-the formation of monomers into macromolecules by condensation reactions
-Requires energy
-Includes:
-Protein synthesis using ribosomes
-DNA synthesis during replication
-Photosynthesis
-Synthesis of complex carbs
Anabolism is an important process in cells. Outline the process of anabolism with reference to an example. (6 marks)
-Synthesis of complex molecules from simpler molecules
-the formation of monomers into macromolecules by condensation reactions
-Requires energy
-Includes:
-Protein synthesis using ribosomes
-DNA synthesis during replication
-Photosynthesis
-Synthesis of complex carbs
Outline how monosaccharides are converted into polysaccharides. (2 marks)
-condensation;
-involves the removal of water to join monosaccharides together;
-catalysed by enzymes;
-consists of many monosaccharides linked (glycosidic) to make polysaccharide
Discuss why ribose and glucose are most similar in structure. (3 marks)
-both are monosaccharides / sugars / reducing sugars
-both are ring shaped molecules
-both have one oxygen atom in the ring
-both have the same relative amounts of C, H, and O
What is the difference between galactose and lactose?
Lactose is a disaccharide and galactose is a monosaccharide
How many molecules of water are required to completely hydrolyse a starch molecule made up of 23 molecules of glucose?
22
What is the role of sulfur in living organisms?
Formation of proteins
What is the role of sulfur in living organisms?
Formation of proteins
Outline (give a brief account or summary) the thermal, cohesive and solvent properties of water
Water not dissolved in blood, rather substances are dissolved in water which makes up over 90% of blood
What is denaturation?
A structural change of a protein that results in the loss of its biological properties
state definition of the proteome
the totality of proteins expressed within a cell, tissue or organism at a certain time
What are functions of proteins?
providing structure, regulating body processes, transporting materials, balancing fluids, helping with immunity, and providing energy
Define active site
site on surface of the enzyme to which the substrate binds
list three examples of enzymes and their functions
catalase-breaks down hydrogen peroxide
lactase-digest lactose to glucose and galactose
amylase-digest starch
list three examples of enzymes and their functions
catalase-breaks down hydrogen peroxide
lactase-digest lactose to glucose and galactose
amylase-digest starch
What contributes to the structure of an enzyme?
Sequence of amino acids linked by peptide bonds
Explain how the active site promotes enzyme-substrate specificity. (2 marks)
-shape of active site matches that of the substrate;
-chemical properties/charges of active site attract the substrate;
-active site can change to induce fit of substrate;