2 Proteins and enzymes

Question 1

What monomers are proteins made up of?

Answer 1

amino acids

Question 2

Fibrous proteins form long _______ chains and have _______ functions, such as collagen

Answer 2

fibrous proteins have long parallel chains and have structural functions, such as collagen

Question 3

Globular proteins are ______ and have many _______ functions (e.g., enzymes)

Answer 3

globular proteins are spherical and have many metabolic functions (e.g., enzymes)

Question 4

What are the 2 groups common to all amino acid molecules?

Answer 4

amine group and carboxyl group

Question 5

What does the R group on an amino acid represent?

Answer 5

a side group/ chain

Question 6

What type of bond is formed when 2 amino acids join?

Answer 6

peptide bond

Question 7

What is a molecule called that is made up of 2 amino acids?

Answer 7

dipeptide

Question 8

What is a molecule called that is made up of many amino acids?

Answer 8

polypeptide

Question 9

What is a molecule called that contains one or more polypeptides?

Answer 9

functional protein

Question 10

What does a protein with a primary structure look like?

Answer 10

a polypeptide chain, no extra bonding

Question 11

Describe the primary structure of a protein

Answer 11

sequence of amino acids in polypeptide chain

Question 12

What 2 forms can secondary structures of a protein take?

Answer 12

alpha helix or beta-pleated sheet

Question 13

What type of bond is involved in secondary structure formation of proteins?

Answer 13

hydrogen bond

Question 14

Which 3 bonds can form between polypeptides in tertiary protein structures creating their shape?

Answer 14

hydrogen, ionic, disulfide bonds

Question 15

Describe the quaternary structure of a protein

Answer 15

separate polypeptides linked together

Question 16

Where does the reaction take place in an enzyme?

Answer 16

active site

Question 17

What is formed when the substrate has attached to an enzyme?

Answer 17

enzyme-substrate complex

Question 18

Enzymes are biological _______

Answer 18

enzymes are biological catalysts

Question 19

Enzymes are ________ to a particular substrate

Answer 19

enzymes are specific to a particular substrate

Question 20

The active site has a specific 3D shape, which is ____________ to the substrate

Answer 20

the active site has a specific 3D shape, which is complimentary to the substrate

Question 21

Each enzyme lowers the ___________ energy of its reaction

Answer 21

each enzyme lowers the activation energy of its reaction

Question 22

What test is used to identify proteins, and what results are shown when a protein is present?

Answer 22

biuret test- pale blue to lilac

Question 23

What can be carried out to identify the components of a mixture of unknown amino acids?

Answer 23

chromatography

Question 24

What will happen to the rate of an enzyme-controlled reaction if the concentration of enzyme is increased?

Answer 24

it will increase, provided there is enough substrate (more enzyme-substrate complexes)

Question 25

What will happen to the rate of enzyme-controlled reaction if the temperature is increased?

Answer 25

it will increase, until the temperature denatures the enzyme

Question 26

What is a competitive inhibitor?

Answer 26

a non-substrate molecule that fits in the active site of an enzyme

Question 27

Which type of protein structure does haemoglobin have?

Answer 27

quaternary

Question 28

What is a non-competitive inhibitor?

Answer 28

non-substrate molecule that binds to non-functional part of enzyme and changes specific shape of active site

Question 29

What is the accepted model of enzyme action called?

Answer 29

induced-fit model

Question 30

Describe the induced-fit model of enzyme action

Answer 30

- shape of active site of enzyme not fully complementary to substrate molecule - when substrate collides with active site, enzyme changes shape to fit active site around substrate --> enzyme-substrate complex --> reaction