Chapter 2.4 proteins

Question 1

Peptide

Answer 1

two or more amino acids joined by peptide bonds

Question 2

How are peptide bonds formed?
Which functional groups connect peptides together?

Answer 2

Dehydration synthesis

Amino group of one amino acid to carboxyl group of the next

Question 3

3 Characteristics of amino acids

Answer 3

-Central carbon atom with an amino group, carboxyl group, hydrogen, and R group
-All amino acids identical except for radical group
-Often amphipathic

Question 4

Oligopeptide

Answer 4

Chains of amino acids fewer than 10 or 15

Question 5

Polypeptides

Answer 5

10 or 15 or more chains of amino acids

Question 6

How many chains Of amino acids does a polypeptide need to be a protein?

Answer 6

50 or more

Question 7

Primary structure Of a protein And it’s associated bond

Answer 7

Proteins sequence of amino acids; peptide bonds

Question 8

Secondary structures and Associated bond

Answer 8

Alpha helix or beta sheets held together by hydrogen bonds

Question 9

Tertiary structure and associated bonds

Answer 9

further bending and folding of proteins into various globular and fibrous shapes.
Van der waals forces and hydrophilic/phobic interactions

Question 10

Globular proteins

Answer 10

Look like a watered ball of yarn;

-Embedded in cell membranes
-proteins that must move freely like Enzymes and antibodies

Question 11

Fibrous proteins

Answer 11

Slender filaments such as myosin, keratin, and collagen; provide strength to skin hair and tendons

Question 12

Disulfide bridges

Answer 12

-In amino acid cysteine
-Formed by covalent bonds
-Holds tertiary structures (separate polypeptide chains) together.

Question 13

Quaternary structure and associated bonds

Answer 13

-two or more polypeptide chains
-ionic bonds and hydrophilic/hydrophobic interactions
-non-amino moiety: prosthetic group
Ex: hemoglobin

Question 14

Denaturation

Answer 14

Conformation change that breaks hydrogen bonds; lose structure=lose function

Ex: cook egg white 

Question 15

Conjugated protein has what bonded to it and how bonded?

Answer 15

Has a prosthetic group; covalently bonded

Ex: glycoproteins: the carbohydrate moiety is a prosthetic group

Question 16

6 Protein functions:

Answer 16

1. Structure
2. Communication
   3. Membrane transport
3. Catalysis
4. Movement/ adhesion
5.  Recognition

Question 17

Examples of protein structures

Answer 17

Keratin for hair, skin, nails

Collagen for deep layers of skin, bones, cartilage, teeth

Question 18

Protein recognition and protection

Answer 18

-Antibodies and other proteins attack and Neutralize invading organisms. 
-also clotting proteins

Question 19

What are enzymes

Answer 19

Proteins that function as biological catalysts

Question 20

Substrate

Answer 20

The substance the enzyme acts upon

(Adds the suffix -ase
Ex: amylase amyl=starch)

Question 21

Activation energy

Answer 21

The energy needed to get the reaction started; Enzymes lower activation energy needed

Ex: Burning paper: the match supplies activation energy

Question 22

Conformation change is important to what?

Answer 22

enzyme function, muscle contraction, and the opening and closing of pores in cell membranes

Question 23

Enzymes lower the ______ of a reaction 

Answer 23

Activation energy

Question 24

Enzyme structure and action order of events:

Answer 24

1. substrate approach activation site
2. Enzyme – substrate complex (Enzyme – substrate specificity)
3.  Bond broken or formed; enzyme releases product(s)

Question 25

Cofactors of enzymes

Answer 25

non-protein INORGANIC partner

Question 26

Coenzymes

Answer 26

Organic cofactors

Acts as a shuttle that picks up electrons from one metabolic pathway and delivers them to another

Question 27

Metabolic pathway

Answer 27

A chain of reactions with each step usually catalyzed by a different enzyme

Question 28

When a macromolecule is conjugated, it is

Answer 28

Covalently bonded to another macromolecule

Question 29

Conformation

Answer 29

3 dimensional shape

Question 30

Function of a protein is derived from its what?

Answer 30

Structure