Cells and proteins - 2

Question 1

what is proteomics?

Answer 1

the study of an entire set of proteins expressed by the organism’s genome

Question 2

what is a proteome?

Answer 2

set of proteins in an organism

Question 3

why is a proteome larger than a genome?

Answer 3

since alternative RNA splicing and post translation modification means that one gene = many proteins

Question 4

what is alternative RNA splicing?

Answer 4

different mRNA segments can be treated as introns or axons depending on the protein

Question 5

name two types of post translation modification

Answer 5

• addition of a phosphate or carbohydrate

- cleavage

Question 6

what is the structure of an amino acid?

Answer 6

• amide group
• R group
• carboxylic group

Question 7

how do amino acids join together?

Answer 7

in a condensation reaction

Question 8

what type of bonds form when amino acids join together?

Answer 8

peptide bonds

Question 9

what is a chain of amino acids called?

Answer 9

a polypeptide

Question 10

where are the N terminal?

Answer 10

where the NH2 group is

Question 11

where is the C terminal?

Answer 11

where the carboxylic group is

Question 12

what is the primary structure?

Answer 12

the order in which the amino acids are synthesised

Question 13

what are the four classes of amino acids?

Answer 13

• acidic
• basic
• polar
• hydrophobic

Question 14

describe an acidic amino acid

Answer 14

• negatively charged

- R group = carboxylic group

Question 15

describe a basic amino acid

Answer 15

• positively charged

- R group = amide group

Question 16

describe a polar amino acid

Answer 16

• slightly charged

- R group = OH group

Question 17

describe a hydrophobic amino acid

Answer 17

• usually no charge

- R group = hydrocarbon

Question 18

what is the secondary structure?

Answer 18

chain which forms either two structures in which hydrogen bonds keep the structure in place

Question 19

what two types of secondary structures can be formed?

Answer 19

alpha helix or beta-pleated sheets

Question 20

what are the two types of beta-pleated sheets?

Answer 20

anti-parallel sheets or parallel sheets

Question 21

what gives a protein its 3D structure?

Answer 21

different types of bonding forming a tertiary structure

Question 22

what types of bonding can form in a tertiary structure?

Answer 22

• hydrogen bonds
• ionic bonds
• hydrophobic
• van der Waals forces
• disulphide bridges

Question 23

what is a quaternary structure?

Answer 23

proteins with many chains of polypeptides subunits connected together

Question 24

what is a prosthetic group?

Answer 24

non-protein group which is strongly bound to a polypeptide unit

Question 25

what can cause a protein to denature?

Answer 25

temperature and pH

Question 26

what is an R-group?

Answer 26

variable group on an amino acid

Question 27

what are the importances of R-groups on a protein?

Answer 27

• determines the structure of protein
• determines the location within a cell
• call allow bindings of ligands

Question 28

what are cytoplasmic proteins?

Answer 28

soluble proteins that forms a globular structure with hydrophobic core

Question 29

what makes cytoplasmic proteins soluble?

Answer 29

surface has a greater proportion of hydrophilic R groups