Proteins

Question 1

What is the monomer of proteins?

Answer 1

amino acids

Question 2

What elements do proteins contain?

Answer 2

carbon, hydrogen, oxygen, nitrogen

Question 3

What 2 elements could possibly be found in a protein?

Answer 3

sulphur, phosphorous.

Question 4

What is the polymer of proteins?

Answer 4

Polypeptide - chain of amino acids

Question 5

What element is always in a protein?

Answer 5

Nitrogen

Question 6

What is this group called?
(-NH2)

Answer 6

Amine group

Question 7

What is this group called?
(-COOH)

Answer 7

Carboxyl group

Question 8

What is the group that changes in the amino acids called?

Answer 8

Variable R group

Question 9

What is being defined here?
(A reaction takes place between the amino group of one amino acid and the carboxyl group of another)

Answer 9

Peptide bond

Question 10

Describe a peptide bond

Answer 10

A reaction takes place between the amino group of one amino acid and the carboxyl group of another

Question 11

What’s the term for two amino acids bonding?

Answer 11

Dipeptide

Question 12

What reaction takes place during the bonding of amino acids?

Answer 12

Condensation reaction - a molecule of water is formed

Question 13

If a condensation reaction occurs in amino acids, what bond is formed?

Answer 13

Peptide bond

Question 14

Describe the formation of a dipeptide.

Answer 14

Carboxyl group + Amine group –> peptide bond + water molecule

Question 15

How many protein structures are there, list them.

Answer 15

4 - primary, secondary, tertiary and quaternary

Question 16

How many types of secondary protein structures are there?

Answer 16

alpha helix,
beta-pleated sheet

Question 17

Where are the hydrogen bonding in a secondary protein structure?

Answer 17

=O on -CO groups and the -H on -NH groups

Question 18

Long __________ chain twists into ____ shape

Answer 18

polypeptide, 3D

Question 19

What is a protein primary structure?

Answer 19

singular peptide chain

Question 20

What bonds are present in a tertiary protein structure?

Answer 20

Ionic bonds, hydrogen bonds, disulfide bond

Question 21

A tertiary protein structure: the shape is held in place by hydrogen, ionic and disulfide bonds together with ________________.

Answer 21

hydrophobic interactions

Question 22

What does a quaternary protein structure consist of?

Answer 22

2 or more tertiary bonded together

Question 23

Give one example of a quaternary protein structure in the human body

Answer 23

haemoglobin

Question 24

How many polypeptide chains does haemoglobin consist of?

Answer 24

4

Question 25

What is the iron-containing group called in the centre of each polypeptide chain in haemoglobin?

Answer 25

Haem

Question 26

Describe why the maximum number of oxygen molecules each haemoglobin molecule can pick up is four.

Answer 26

Each haem group contains an iron ion (Fe2+). Since each iron ion can bond with one molecule of oxygen, each haemoglobin can pick up four oxygen molecules.

Question 27

What is the fibrous proteins we must learn?

Answer 27

Collagen

Question 28

What's the formation of parallel chain in collagen?

Answer 28

Polypeptides laid down in parallel chains

Question 29

Describe 3 properties of fibrous proteins.

Answer 29

very stable, insoluble and strong

Question 30

Describe a collagen fibre - the polypeptide chains and bonds

Answer 30

Three polypeptide chains and each is twisted in the form of alpha-helix. Hydrogen bonds hold three strands in place.

Question 31

Pair globular proteins/Fibrous proteins with soluble in water/insoluble in water

Answer 31

Globular are soluble in water. Fibrous are insoluble in water.

Question 32

globular proteins/Fibrous proteins stable/not stable

Answer 32

Globular proteins are easily changed chemically therefore not stable. Fibrous are stable and tough

Question 33

globular proteins/Fibrous proteins metabolic functions/structural functions

Answer 33

Globular - metabolic functions. Fibrous - structural functions

Question 34

What solution is used to test for the presence of protein and what are the colour change?

Answer 34

Biuret reagent pale blue to lilac/purple

Question 35

Describe what is meant by QUALITATIVE

Answer 35

results indicates whether food group is present or not

Question 36

Describe what is meant by SEMI-QUSNTITATIVE

Answer 36

different colour changes can indicate different concentrations

Question 37

Describe what is meant by QUANTITATIVE.

Answer 37

actual value for the concentration of food group present

Question 38

Primary protein structure - what determines the sequence of amino acids?

Answer 38

Base sequence on a strand if the DNA molecule