Introduction to AS Biology - Enzymes and Proteins

Question 1

What is every enzyme?

Answer 1

A protein, which is a chain of amino acids

Question 2

Describe the size of enzymes

Answer 2

Very large compared to other compounds

Question 3

What is the main purpose of enzymes to be?

Answer 3

Biological catalysts

Question 4

Biological catalysts

Answer 4

Biological - made by living cells
Catalysts - a substance which increases the rate of a reaction without itself undergoing permanent chemical change (can be re-used)

Question 5

What’s is a Buffer solution?

Answer 5

It maintains the pH of a reaction (most enzymes work best at a pH of 7)

Question 6

How do most enzymes work best?

Answer 6

At a pH of 7

Question 7

How do enzymes work as catalysts?

Answer 7

Enzymes reduce the activation energy of a reaction, making the reaction faster
(heat is normally used to give energy for a reaction to start, yet this can damage cells)

Question 8

What are Proteins?

Answer 8

Biological compounds formed from smaller molecules known as amino acids joined by covalent bonds

Question 9

Which group of Biological compounds do all enzymes belong to?

Answer 9

Proteins

Question 10

Which groups do you have on the amino acids structure?

Answer 10

-Hydrogen on its own
-Amine group
-Carboxyl group
-Variable group

Question 11

Amine group (amino acids)

Answer 11

H
I
H _ N

Question 12

Carboxyl group (amino acids)

Answer 12

O
II
C _ OH

Question 13

How many different amino acids are there?

Answer 13

20

Question 14

How do you link different amino acids together and what does this do?

Answer 14

H from the amine group and HO from the carboxyl group form H20 and is replaced with a peptide bond, to make a protein. This process is controlled by the DNA.

Question 15

Type of bond linking amino acids

Answer 15

Peptide

Question 16

Which elements do all biological compounds contain?

Answer 16

Carbon, hydrogen and oxygen

Question 17

Which additional compounds to usual biological compounds do amino acids contain?

Answer 17

Nitrogen and sometimes sulphur

Question 18

What’s the name given to a long chain of amino acids?

Answer 18

Polypeptide

Question 19

What type of shape to enzyme molecules have and why?

Answer 19

A distinct 3D shape as the polypeptide folds in a very specific way

Question 20

What’s the name of the molecule that reacts with an enzyme?

Answer 20

A substrate molecule

Question 21

How do reactions happen with enzymes?

Answer 21

The substrate molecule fits precisely into the active site of the enzyme molecule in order for a reaction to happen. The shape of the active site is complementary to the shape of the substrate molecule.

Question 22

How does the shape of the active site compare to the shape of the substrate molecule?

Answer 22

The shape of the active site is COMPLEMENTARY, not the same

Question 23

What is the name of the hypothesis which explains how enzymes work?

Answer 23

Lock and key hypothesis

Question 24

What is the smallest unit of a protein molecule called?

Answer 24

Amino acid

Question 25

What happens when substrates enter the active site of an enzyme?

Answer 25

It fits so that the enzyme can catalyse the reaction and holds them so that the groups on the molecule are close

Question 26

Why are enzymes specific?

Answer 26

So that they only catalyse one specific type of reaction, and so that the substrate fits into the active site - it is complementary to it

Question 27

Name 2 enzyme catalysed reactions

Answer 27

1 - Catalase enzyme catalyses the substrate hydrogen peroxide (H202) to give water and oxygen
2 - Lactase enzyme catalyses the lactose substrate to give galactose and glucose molecules

Question 28

What is hydrogen peroxide?

Answer 28

A poison that our cells sometimes create as a byproduct in metabolic reactions, hence the existence of catalase

Question 29

Slightly random BUT why would you mince a potato before doing an enzyme experiment on it?

Answer 29

To increase its surface area for the enzymes to work on

Question 30

Why can enzymes catalyse time and time again?

Answer 30

As they aren’t chemically altered by reactions as they’re catalysts

Question 31

What type of bonds join amino acids?

Answer 31

Covalent bonds

Question 32

What’s a molecule? How do we differentiate between different ones?

Answer 32

2+ atoms
If they’re the same, it’s of an element
If they’re different, it’s a compound

Question 33

What can compounds include?

Answer 33

Metals + non-metals = ionic
Just non-metals = molecular

Question 34

A lack of which ions could disrupt nervous coordination?

Answer 34

Sodium and potassium

Question 35

Which ion is involved in blood transportation alongside iron?

Answer 35

Chlorine

Question 36

What’s important to do on a comparison question?

Answer 36

Make clear comparisons

Question 37

Under which conditions is there less enzyme activity?

Answer 37

Colder conditions

Question 38

How do cold conditions affect enzyme activity?

Answer 38

Less of it

Question 39

Thylocoid in the chloroplasts function

Answer 39

Site of light dependant reaction - allow photosynthesis

Question 40

Stroma in chloroplasts function

Answer 40

Fluid that includes enzymes for catalysing photosynthesis reactions (light INdepdndant)

Question 41

Out of stroma and thylocoids functions, which ones are light dependant?

Answer 41

Thylocoids - light dependant
Storms - light independant