Biological molecules 1: Proteins

Question 1

What are proteins

Answer 1

Proteins are biological molecules made up by one or more polypeptides joined together a series of peptide bonds through condensation reactions

Question 2

What is the monomer of a protein

Answer 2

Amino acids

Question 3

What is a dipeptide

Answer 3

Two amino acids joined together by a peptide bond through a condensation reaction

Question 4

What are polypeptides

Answer 4

Polypeptides are two or more amino acids joined together by peptide bonds through condensation reactions

Question 5

How many variations amino acids are there

Answer 5

20

Question 6

What are the differences bettween the amino acids

Answer 6

Their R groups

Question 7

What bonds occur between the formation of dipeptides and polypeptides

Answer 7

Peptide bonds

Question 8

What groups on the amino acids does bonding occur between

Answer 8

An amine group on one amino acid and a carboxyl group of another

Question 9

What is the primary structure of a protein

Answer 9

The sequencing of amino acids in a polypeptide chain

Question 10

What is the secondary structure of a protein

Answer 10

The coiling and folding of the polypeptide chain based on the sequencing of amino acids

Question 11

What forms during the secondary structure

Answer 11

Alpha (α) helices
Beta (β) pleated sheets

Question 12

What is the tertiary structure of a protein

Answer 12

The further coiling and folding of a polypeptide chain causing a 3D structure held together by different interactions between R groups of amino acids

Question 13

What is the quaternary structure of a protein

Answer 13

The structure formed when two or more polypeptide chains joined together

Question 14

What are the two main 3D structures that occur during the tertiary structure

Answer 14

Fibrous structure
Globular structure

Question 15

When do hydrogen bonds occur during the tertiary structure

Answer 15

They occur when their are different attractions between negative and positive charges of different parts of the molecule

Question 16

When do disulphide bridges occur during the tertiary structure

Answer 16

They occur when two cysteine are close together and a sulphur atom in one cysteine bonds with a sulphur on another - causing a double bond between them

Question 17

What do the ionic bonds form between in the tertiary structure

Answer 17

They form between the opposite attraction of the negative and positive charges of the R groups on amino acids

Question 18

What structures do globular proteins form

Answer 18

Round and spherical structures

Question 19

What structures do fibrous proteins form

Answer 19

Long and narrow structures

Question 20

What is the structure of an enzyme and how does it help with its function

Answer 20

Globular structure - Folded in a way where it has the correct orientation and active site as it’s substrate so can form enzyme substrate complexes

Question 21

What structure do antibodies have and how does it help its function

Answer 21

Globular structure - Easy to transport meaning they can get to antigens quickly

Question 22

What structure do transport proteins have and how does it help its function

Answer 22

Globular structure - Contains both hydrophobic and hydrophilic amino acids causing protein to fold up into a channel

Question 23

What structure do structural proteins have and how does it help its function

Answer 23

Fibrous structure - Long polypeptide chain lay parallel to each other with cross links between them making them very strong

Question 24

What shape are fibrous proteins

Answer 24

Long and narrow

Question 25

What shape are globular proteins

Answer 25

Round and spherical

Question 26

What function do fibrous proteins have

Answer 26

Structural

Question 27

What function do globular proteins have

Answer 27

Functional

Question 28

What causes fibrous proteins to have a long and narrow shape

Answer 28

Their amino sequencing is repetitive

Question 29

What causes globular proteins to have a round and spherical shape

Answer 29

Irregular amino acid sequencing

Question 30

Examples of fibrous proteins

Answer 30

Collagen and Keratin

Question 31

Examples of globular proteins

Answer 31

Enzymes and haemoglobin

Question 32

What is glycine

Answer 32

An amino acid with an R group only containing a hydrogen

Question 33

What binds are present in the tertiary of a protein

Answer 33

• Ionic bonds
• Disulphide bridges
• Hydrogen bonds