Protein structure and enzymes

Question 1

Amino acids

Answer 1

Monomers of proteins

Question 2

Bond formed when amino acids bond together

Answer 2

Dipeptide bond

Question 3

Polypeptide

Answer 3

When more than two amino acids join together

Question 4

Condensation reaction to form polypeptides

Answer 4

Amino acids are joined together with a peptide bond forming between Carbon of a carboxyl group and Nitrogen of an amine group. Water is formed as product

Question 5

Primary structure

Answer 5

The sequence of amino acids in a polypeptide chain held together by peptide bonds

Question 6

Secondary structure

Answer 6

Hydrogen bonds from between amino acids in the chain and makes it coil into an alpha or fold into a beta pleated sheet

Question 7

Tertiary structure

Answer 7

The coiled or folded amino acids go further into their final 3D structure with more bonds forming between different parts of the polypeptide chain including hydrogen, disulfide bridges ionic bonds and hydrophobic/philic interactions

Question 8

Quaternary structure

Answer 8

When polypeptide chains are assembled together

Question 9

Globular proteins

Answer 9

Round, compact proteins made up of multiple polypeptide chains
Hydrophobic parts of the chain face inwards and hydrophilicface outwards making it soluble

Question 10

Adaptations of haemoglobin

Answer 10

It is a globular protein so it is soluble and can be easily transported in the blood
Contains iron containing haem groups to bind to oxygen

Question 11

Fibrous proteins

Answer 11

Long molecules made of insoluble peptide chains that are tightly coiled together
Lots of bonds between the chains make it a strong molecule, so they are often found in supportive tissue q

Question 12

Collagen adaptions

Answer 12

Strong fibrous protein found in connective tissue in animals

Question 13

Enzymes

Answer 13

Biological catalysts which lower the activation energy of chemical reactions

Question 14

Where are enzymes found

Answer 14

Everywhere, intracellular and extracellular

Question 15

Enzyme substrate complex

Answer 15

When a substrate binds to the active site of an enzyme

Question 16

How do enzymes reduce activation energy

Answer 16

Holds substrate molecules close together reducing any repulsion so they can bond more easily
Puts strain on bonds in a substrate so it breaks up more easily

Question 17

Induced fit model

Answer 17

Active site changes shape when he substrate binds

Question 18

Properties of enzymes

Answer 18

Specific so only one complementary substrate will fit onto active site
Each different enzyme has a different tertiary structure so different shaped active site

Question 19

Active site shape

Answer 19

Determined by the tertiary structure of the enzyme, which is determine by primary structure

Question 20

How is tertiary shape of enzyme altered

Answer 20

Temperature or pH

Question 21

Saturation point

Answer 21

When the concentration of enzymes becomes the limiting factor, so adding more sublates doesn’t change anything

Question 22

Why is initial rate of reaction the highest

Answer 22

Substrate concentration decreases over time so rate of reaction decreases as well