Ch 5 - Pt 2 - Proteins

Question 0

Enzyme

Answer 0

Proteins that serve as catalysts in living organisms; typically very large molecules that bring together/break apart substrates (the molecules upon which a chemical reaction occurs).

Question 1

Catalyst

Answer 1

A substance that accelerates the rate if a chemical reaction without affecting the products of the reaction and without itself being altered or consumed by the reaction.

Question 2

Amino acids

Answer 2

An organic molecule possessing both an amino acid and a carboxyl group.

The monomer building blocks of proteins.

Question 3

Polypeptides

Answer 3

Polymers of amino acids

A protein consists of one or more polypeptides

Question 4

Amino acid monomers

Answer 4

Organic molecules possessing both carboxyl and amino groups. Differ in their properties due to differing side chains (R-groups).

Question 5

How many different amino acid monomers from which polypeptides are assembled?

Answer 5

20

Question 6

Peptide bonds

Answer 6

The covalent bond between the carboxyl group of one amino acid and the amino group on another formed by a dehydration reaction.

The link between amino acids.

Dehydration reaction.

Question 7

How are peptide bonds formed?

Answer 7

Through dehydration reactions.

Question 8

How does a protein’s specific conformation/3D shape effect it’s function?

Answer 8

A protein’s specific conformation determines its function

Question 9

What are some examples of models depicting a proteins specific conformation (3D shape)?

Answer 9

Space-filling model, ribbon model, 3D complementarity between an antibody protein and an invading virus particle

Question 10

What are the 4 levels in protein structure?

Answer 10

Primary, secondary, tertiary, and (in some cases) quaternary structure

Question 11

Primary structure of a protein

Answer 11

1) The linked series of amino acids with a unique sequence.
2) The 29 amino acids can be assembled into 20^127 sequences.
3) Primary structure dictates structure at higher levels.

Question 12

Secondary structure of proteins

Answer 12

Hydrogen bonds between amino acids of a single polypeptide (a helix) or amino acids of adjacent polypeptides (B sheet) bring about secondary structure

Question 13

Tertiary structure if proteins

Answer 13

1) Results from interactions between the side chains (R-groups) of amino acids
2) Involves a variety of bonds: disulfide bridges, hydrogen bonds, van der Waals interactions, ionic bonds

Question 14

Quaternary structure of proteins

Answer 14

Are comprised of 1+ polypeptide subunits

Question 15

Example of the importance of primary structure

Answer 15

Sickle-cell hemoglobin differs from normal hemoglobin in only one amino acid

Question 16

Denaturation

Answer 16

Occurs when a protein unravels and loses its 3D confirmation

Ex: cooking meat, ceviche

Question 17

Protein functions

Answer 17

Enzymes, structural proteins, storage proteins, transport proteins, hormones, receptor proteins, contractile and motor proteins, defensive proteins

Question 18

Structural proteins

Answer 18

Keratin: structural protein in hair, nails, etc
Collagen: the most abundant protein in animals and provides the high tensile strength and resilience in skin, tendons, and ligaments

Question 19

Storage proteins

Answer 19

Ovalbumin (albumin): egg white is 10% protein dissolved in water and serves as a source of nutrition for a developing embryo

Question 20

Hormone (proteins)

Answer 20

Insulin: a protein hormone produced in the pancreas; regulates carbohydrate metabolism

Question 21

Receptor proteins

Answer 21

Transmembrane receptor proteins can pump molecules against their diffusion gradient and are also involved in promoting and regulating chemical reactions in cells

Question 22

Contractile and motor proteins

Answer 22

Dynein: the motor protein that moves material within the cell by “walking” along support structures in cells

Question 23

Defensive proteins

Answer 23

Antibodies are protein signals and binding sites for components of the immune system.
(Ex: the venom of stingrays)

Question 24

Protein

Answer 24

A biologically functional molecule that consists of one or more polypeptides, each folded and coiled into a 3D structure