Biological Molecules Pt2

Question 1

What are amino acids

Answer 1

The monomer from which proteins are made

Question 2

What is the structure of an amino acid

Answer 2

R

H2N — C — COOH

         H

Question 3

What is the structure of an amine group

Answer 3

NH2

Question 4

What is the structure of a carboxyl group

Answer 4

COOH

Question 5

What does the R represent in an amino acid

Answer 5

The side chain, each one has a different one

Question 6

What reaction joins 2 amino acids together and what is formed

Answer 6

Condensation reaction forms a peptide bond

Question 7

What is a dipeptide

Answer 7

Condensation reaction between 2 amino acids

Question 8

What is a polypeptide

Answer 8

Condensation of many amino acids

Question 9

Functions of protein

Answer 9

1. Enzymes - functional proteins
2. Blood clotting - defence proteins
3. Hormones
4. Antibodies

Question 10

What is primary structure of a protein

Answer 10

The order of amino acids (a chain), changing one may alter properties completely

Question 11

What is the secondary structure of a protein

Answer 11

When a polypeptide folds a fully functional protein is produced :
1. Alpha helix
2. Beta pleated sheet
Bonds = hydrogen bonds between - charge on carboxylic acid groups and + charge on amino acids

Question 12

What is the tertiary structure of a protein

Answer 12

The a-helix or b-pleated sheet fold further to give a unique tertiary structure held together by:
1. Hydrogen bonds between r groups
2. Hydrophobic interactions
3. Ionic bonds (strong)
4. Disulphide bridge (string)

Question 13

What is the quaternary structure of protein

Answer 13

When more than 1 polypeptide chain is bound together

Question 14

What are the 2 types of quaternary structure

Answer 14

1. Globular - e.g haemoglobin
2. Fibrous- e.g collagen (triple helix)

Question 15

What is a conjugated protein

Answer 15

A protein to which another chemical group is attached e.g lipoprotein

Question 16

Biuret test

Answer 16

Add biuret solution into solution if protein present blue —> purple

Question 17

Function of dna

Answer 17

Holds genetic information

Question 18

Function of rna

Answer 18

Transfers genetic info from dna to ribosomes

Question 19

What are rna and dna polymers of

Answer 19

Nucleotides

Question 20

What makes up a nucleotide

Answer 20

• pentose
• nitrogen containing organic base
• phosphate group

Question 21

Components of a dna nucleotide

Answer 21

Deoxyribose, phosphate group and one of organic bases:adenine, thymine, guanine or cytosine

Question 22

Components of an rna nucleotide

Answer 22

Ribose, phosphate group, of of organic bases: adenine, uracil, guanine, cytosine

Question 23

What does a condensation reaction between 2 nucleotides form

Answer 23

A phosphodiester bond

Question 24

What is a dna molecule

Answer 24

A double helix with 2 polynucleotide chains held together by hydrogen bonds between specific complementary base pairs

Question 25

What is an rna molecule

Answer 25

A relatively short polynucleotide chain

Question 26

Why is dna a stable molecule

Answer 26

1. Phosphodieseter backbone protects the more reactive bases 2. Hydrogen bonds link the base pairs, forming bridges between the phospodiester upright strands

Question 27

Structure and function of dna

Answer 27

1. Stable molecule so passes from generation to generation without much change 2. 2 strands only joined by h bonds so can easily be separated during dna replication 3. Extremely large molecule so carry’s lots of info 4. Helical shape means genetic material is protected 5. Base pairing means dna is able to replicate and transfer info as mRNA

Question 28

Differences between rna and dna

Answer 28

- rna single stranded dna double - rna uracil dna thymine - rna ribose dna deoxyribose - rna no h bonds dna h bonds - rna no complemtary base pairing dna does

Question 29

Which bases are larger and how many h bonds do they have

Answer 29

G and a larger, c and t smaller Gc 3h bonds At 2 h bonds

Question 30

What is ATP made up of

Answer 30

A base (adenine) a sugar (ribose) 3 inorganic phosphate groups

Question 31

What happens when ATP is hydrolysed

Answer 31

ATP + WATER —> ADP +Pi + energy

Question 32

What enzyme catalysises the hydrolysis of atp

Answer 32

ATP hydrolase

Question 33

What is atp used for

Answer 33

Main source of energy to carry out processes within cells

Question 34

How can the inorganic phosphate that is released during the hydrolysis of ATP be used

Answer 34

To phosphorylate other compounds, making them more reactive

Question 35

3 ways of phosphorylation

Answer 35

1. Photophosphorylation (in chlorophyll containing plant cells during photosynthesis) 2. Oxidative phosphorylation (in animals + plants during respiration) 3. Substrate level phosphorylation

Question 36

How is ATP resynthesised

Answer 36

The condensation of ADP and Pi and is catalysed by ATP synthase during photosynthesis or respiration