Name:__________________________
SBI 3UC Biochemistry Review
(no DNA, no Replication, transcription or translation)
1. What is a hydrocarbon?
a. An organic compound that contains only hydrogen and carbons.
2. What is a glycosidic linkage? An ester linkage? A peptide linkage?- what functional groups are
involved in each of these reactions?
a. Glycosidic-bond resulting from a condensation reaction between sugars
b. Ester linkage- a bond formed between glycerol and a fatty acid from a condensation
reaction
c. Peptide- a bond between the amino group and the carboxyl group of amino acids
3. What is the functional group found in an amino acid? Draw it.
a. NH2-amino and COOH-carboxyl
4. What is a phosphate group? Where is it found?
a. A phosphate group PO4- is found in ADP/ATP and phospholipids
5. What is an essential amino acid?
a. An amino acid that is used to build proteins that cannot be synthesized by the body. They
must be ingested. 8 of the 20 are essential.
6. Which type of macronutrient contains the most energy per gram?
a. Fats/lipids
7. Which compound type is principally used for energy?
a. Carbohydrates are digested first (easiest) then lipids and then proteins.
8. What are the functional groups found in a fatty acid?
a. COOH
9. What is the reaction called that forms the bonds between glycerol and the fatty acids? What
functional groups are involved?
a. Ester. Hydroxyl (alcohol-OH) and carboxyl (COOH)
10. What is a condensation reaction?
a. A synthesis reaction involving the removal of water
11. What is a catabolic reaction
a. A reaction that breaks macromolecules. Ex. Hydrolysis breaks molecules by adding water
12. What is hydrolysis?
a. A catabolic reaction that involves the addition of water to break bonds.
13. What is required for the synthesis of proteins, lipids/fats and carbohydrates?
a. A synthesis reaction (condenstation)
i. Protein- reaction of amino group and carboxyl=peptide linkage
ii. Lipid- ester linkage of hydroxyl and carboxyl
iii. Sugar-glycosidic linkage removal of water (OH and H)
14. What allows for the diversity seen in proteins?
a. R groups are different between different amino acids
b. The sequence of a.a is different between different peptide chains
Name:__________________________
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c. The unique interplay of R group and sequence leads to variability in bonding, which leads to
different shapes.
ALL COMES DOWN TO DIFFERENT R GROUPS AND A.A SEQUENCES
What is glycogen?
a. A short term storage polysaccharide. Long branched chain of glucose molecules stored in
the liver and muscle. Helps regulate glucose in blood. If not used up, converted to fat.
What are the strongest bonds involved in maintaining the shape of an enzyme?
a. Ionic-covalent(S-S)-intramolecular bonds
What is a function of sodium in our body? Phosphorus?
a. Sodium- ion channels
b. Phosphorus- in phospholipids, ATP and DNA/RNA
What are covalent (disulfide bonds)?
a. A bond between two sulfur atoms within proteins.
What are dipole-dipole interactions?
a. An intramolecular bond that occurs between oppositely charged poles in a polar molecule
When are hydrogen bonds used?
a. They are used in the secondary structures of proteins; alpha helix or beta pleated
When would you see hydrophobic bonding?
a. Between two non-polar molecules
When do we see ionic interactions?
a. In tertiary and quaternary structure of proteins
In questions 18-22 which is the strongest bond?
a. Ionic or covalent
State the importance of enzymes?
a. They increase the rate of reaction by lowering activation energy
What is allosteric inhibition? Allosteric activation? What is negative feedback? What is
competitive and non-competitive inhibition?
a. Allosteric inhibition- when a non-competitive inhibitor binds to the allosteric site of an
enzyme and it stabilizes the inactive form of the enzyme.
b. Allosteric activation- when a substance binds to the allosteric site changing the enzyme
structure to be active/free to bind to the substrate(s).
c. Negative feedback- where a product of a biochemical pathway inhibits the action of an
earlier enzyme blocking the production of products
d. Competitive- inhibitor binds to the active site to block enzyme function
e. Non-competitive-bind anywhere other than the active site to block enzyme function
What is a substrate?
a. The reactant
What is an allosteric site?
a. A site where substances can bind other than the active site
What is an activator?
a. A substance that binds to the allosteric site and stabilizes the active form of an enzyme
What is an active site?
Name:__________________________
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a. The site where substrates bind to react
State the factors affecting enzyme function.
a. pH, temperature, enzyme concentration, substrate concentration
Explain how does temperature chemically/structurally affect an enzyme.
a. Denatures the enzyme at higher temperatures
Explain how does pH chemically/structurally affect an enzyme.
a. Denatures the enzyme at pH’s outside the enzymes preferred range of action
What are the different structures of a protein? What bonds are associated with each of these
structures?
a. Primary=amino acid sequence
b. Secondary-alpha helix or beta pleated; H-bonds
c. Tertiary-Covalent bonds, ionic, intramolecular bonds
d. Quaternary- same bonds as above but with more than one protein
What is the difference between the different structures of proteins?
a. See above
What is the difference between beta pleated sheets and alpha helix structures?
a. Beta pleated has a folded shape (stronger) and alpha helix is coiled
Why is water significant to living organisms? Outline using water’s properties.
a. surface tension – allows some organisms (e.g. insects) to move on water's surface;
polarity / capillarity / adhesion – helps plants transport water;
transparency – allows plants to photosynthesise in water / allows animals to see;
(excellent) solvent – capable of dissolving substances for transport in organisms;
(excellent) thermal properties (high heat of vaporization) – excellent coolant;
ice floats – lakes / oceans do not freeze, allowing life under the ice;
buoyancy – supports organisms;
structure – turgor in plant cells / hydrostatic skeleton;
habitat – place for aquatic organisms to live;
involved in chemical reactions in organisms; See notes for details…
37. How are monosaccharides converted to polysaccharides?
a. A condensation reaction that removes an H20 molecule forming a glycosidic linkage
between subsequent monosaccharides.
38. What is a source of an unsaturated lipid? Outline two functions of lipids in the body.
a. Animal fat-lard or butter=saturated and unsaturated are plant oils-coconut oil
b. Phospholipid=cell membrane, energy storage / energy supply; hormone production;
cushioning/protection; insulation; myelin sheath covering nerve axons
39. Outline the use of carbohydrates and lipids in energy storage.
a. The breakdown of glucose provides energy that can be stored within ATP. Easiest and
fastest energy source
b. lipids have more/twice the energy content per unit mass of carbohydrates;
energy stored as glycogen in animals/fungus;
Name:__________________________
c. glycogen/carbohydrates used for short-term energy storage; glycogen converted to glucose
when energy is required;
d. energy stored as starch in plants;
e. lipids/triglycerides used for long-term energy storage; triglycerides converted to fatty acids and
glycerol (when energy is required)
40. Outline the production of a dipeptide by a condensation reaction. Draw it as a chemical reaction.
a. An H from an amino group is removed and an OH from the carboxyl group is removed. This
is a condensation reaction, whereby water is removed to form a peptide bond.
41. List 4 functions of proteins and give an example for each.
a. storage – zeatin (in corn seeds) / casein (in milk);
transport – hemoglobin / lipoproteins (in blood);
hormones – insulin / growth hormone / TSH / FSH / LH;
receptors – hormone receptor / neurotransmitter receptor /
receptor in chemoreceptor cell;
movement – actin / myosin;
defence – antibodies / immunoglobin;
enzymes – catalase / RuBP carboxylase;
structure – collagen / keratin / tubulin / fibroin;
electron carriers – cytochromes;
pigments – opsin
active transport – sodium pumps / calcium pumps;
facilitated diffusion – sodium channels / aquaporins;
42. Explain how allosteric control, by end-product inhibition includes negative feedback and noncompetitive inhibition.
a. allosteric enzyme has binding site(s) away from/other than the active site;
(shape of an) allosteric enzyme alternates between active and inactive (form);
non-competitive inhibitor binds to allosteric site/away from active site;
non-competitive inhibitor changes shape of active site;
non-competitive inhibitors do not compete with substrate for the active site;
Name:__________________________
end-product can inhibit enzyme needed for early/first step in metabolic pathway;
negative feedback since increased level of product decreases rate of its own production;
metabolic pathway regulated according to the requirement for its end-product;
idea that inhibition is reversible;
43. Draw the structure of glucose.
44. Draw the structure of a fatty acid with 6 carbons.
a. HOOC-CH2-CH2-CH2-CH2-CH3
H
45. Draw ribose.
46. Draw an amino acid (general structure)
Name:__________________________
47. Draw the formation of maltose
48. Describe how polar/non polar amino acids are important for membranes
a. Form protein channels that are able to either transport polar or non-polar substance into
and out of a cell
FRUCTOSE!!!!
Break down
10 multiple choice
10 matching
Name:__________________________
52 marks short answer (including 1 data base question)
***if asked to state something from a graph give actual value from graph