bio chem

Question 1

ionic bonding

Answer 1

occurs when a metal lose electrons and becomes positively charged. non-metals gain those electrons and become negatively charged

the two opposite charges come together to form an ionic bond

Question 2

covalent bonding

Answer 2

occurs when two non-metals share electrons

Question 3

two types of covalent bonding

2

Answer 3

polar covalent: unequal sharing between electrons
non-polar covalent: equal sharing between electrons

Question 4

hydrogen bonding

2

Answer 4

• strongest van der waals forces and most biologically significant
• forms between H and one other molecule such as N, O, F

Question 5

glycosidic linkage

2

Answer 5

• carbs
• joins the monosaccharides into larger carbohydtates

(disaccharides and polysaccharides)

Question 6

peptide bond

3

Answer 6

• proteins
• covalent bond between the amino group and carboxyl group of 2 amino acids
• When the carboxyl group of one amino acid is next to the amino group of the another amino acid, a dehydration (or condensation) reaction will join them together with a peptide bond.

Question 7

phosphodiester bond

2

Answer 7

• nucleic acid
• 2 strands composed of repeated nucleotide subunits connected by a phosphodiester linkage/bond

Question 8

ester bond

2

Answer 8

• fats
• When a glycerol molecule reacts with fatty acids, a condensation (or dehydration) reaction occurs between the hydroxyl (-OH) and carboxyl (-COOH) functional groups

Question 9

dehydration/condensation reactions

Answer 9

Used by cells to synthesize larger molecules.

Question 10

hydrolysis

2

Answer 10

• Opposite of a dehydration reaction
• Water (H2O) is the reactant that splits the molecule into smaller subunits.

Question 11

primary structure

2

Answer 11

• specific linear sequence of amino acids.
• If one amino acid is changed in the sequence, it could render the protein dysfunctional.

Question 12

secondary structure

3

Answer 12

• folds and coils at various locations of polypeptide due to hydrogen bonding in
  the polypeptide backbone.
• β-pleated sheet - 2 parallel polypeptide chains joined to one another by hydrogen bonds
• α-helix: Hydrogen bonding between every fourth amino acid, creating a coil shape Ex. keratin = fibrous protein in hair

Question 13

tertiary structure

Answer 13

3D structure is determined by intermolecular reactions between R-groups in the
polypeptide chain.

Question 14

quarternary structure

Answer 14

some proteins consist of 2 or more polypeptide chains aggregated into one functional macromolecule

Question 15

denaturation

3

Answer 15

• Enzymes are proteins
• However, if pH, [salt], temperature, etc. in the environment are altered, the protein may unravel or change shape
• When a protein changes shape no longer carries out its original function

Question 16

activation energy

2

Answer 16

• All chemical reactions require energy in order to take place.
• Enzymes (catalysts) work by lowering the activation energy of chemical reactions

Question 17

cofactors: inorganic

Answer 17

Non-proteins (often metals like Fe, Cu, Zn & Mn) that can bind to an enzyme and are essential for the catalytic activity of the enzyme that they bind to

Question 18

coenzymes: organic

Answer 18

responsible for shuttling molecules from one enzyme to another

Question 19

competitive inhibitors

Answer 19

Similar in structure to the substrate and are able to bind with the active site and block the normal substrate from binding

Question 20

noncompetitive inhibitors

Answer 20

Attach to a different site on the enzyme which changes its shape causing the substrate to not bind properly

Question 21

allosteric regulation

5

Answer 21

• Allosteric regulation can either inhibit or stimulate enzyme activity
• There are regulatory molecules that can bind to a different site than active site called the allosteric site
• When a regulatory molecule binds to the allosteric site it also changes the shape of the active site
• If an allosteric activator binds to the allosteric site, the enzyme will stay functional and stimulate the chemical reaction
• If an allosteric inhibitor binds, the enzyme changes shape and enzymes inactive form is stabilized and will not bind any substrate

Question 22

hydrophobic interactions

Answer 22

non-polar side groups cluster together

Question 23

disulfide bridges

Answer 23

formed between the –SH groups of 2 cysteine amino acids that react to form an S-S covalent bond. This is a strong bond that holds the 3D shape of the protein.

Question 24

intermolecular forces

Answer 24

Intermolecular reactions include:
Ionic bonds, Hydrophobic interactions, Disulfide bridges