carbohydrates exam paper

Question 1

what type of diffusion occurs through a protein channel

Answer 1

facilitated diffusion

Question 2

what kind of molecules can use simple diffusion to move across membranes

Answer 2

small nonpolar molecules

Question 3

what kind of transport is used to allow glucose with sodium irons to cross a membrane?

Answer 3

co-transport

Question 4

describe the induced fit model of enzyme action

Answer 4

The Active site isn’t a complimentary shape to the substrate
when it binds the active site changes shape to allow it to fit
It does this by bending bonds which causes a reaction

Question 5

what reducing sugar would you expect to be produced during chewing?

Answer 5

maltose because the salivary amylase breaks down starch

Question 6

what are the enzymes required for the complete digestion of starch?

Answer 6

Maltase and amylase

Question 7

when investigating the effect of chewing on digestion, why was it necessary for samples to be mixed with water hydrochloric acid and pepsin?

Answer 7

to mimic the effect of the stomach

Question 8

give one reasons why it might be more efficient to attach lactate to beads as opposed to directly adding lactase to cows milk:

Answer 8

1) beads can be reused

Question 9

explain why lactose free milk made after hydrolysis might taste sweeter than cows milk containing lactose

Answer 9

hydrolysis breaks down disaccharides and produces bad components in this case the monosaccharides were galactose and glucose and so more sugars are present 

Question 10

Give two ways in which the structure of starch is similar to Celulose

Answer 10

1) they both contain glycosidic bonds

2) they are both polymers made of monomers 

Question 11

why does maltase only break down Maltose?

Answer 11

The active site of maltase is complementary to the shape of maltose

Question 12

what are enzyme inhibitors?

Answer 12

Inhibitors reduce the binding of enzymes to substrates

Question 13

Describe the competitive inhibition of an enzyme

Answer 13

A competitive inhibitor is usually of a similar/complimentary shape to the active site and so it is able to bind to the active shape of that enzyme

Question 14

describe a non-competitive inhibition of an enzyme

Answer 14

An inhibitor binds to another site on an enzyme other than the active site and prevents the formation of an active site and changes its shape

Question 15

how would you test the sample of food for the presence of starch?

Answer 15

add a drop of iodine and if the sample turns blue black or purple colour starch is present

Question 16

why is the rise in concentration of glucose in the blood slower if a carbohydrate is starch rather than sucrose?

Answer 16

starch requires two enzymes for it to be fully broken down. it first needs to be broken down into maltose by amylase and then maltose digested to glucose by maltase.
Whereas sucrose only needs one sucrase

Question 17

where is the enzyme amylase produced?

Answer 17

pancreas

Question 18

what is the product of a reaction catalysed by amylase?

Answer 18

maltose

Question 19

where is the enzyme maltase produced?

Answer 19

In the Epithellium

Question 20

what is the product of a reaction catalysed by maltase

Answer 20

glucose

Question 21

how do use a biochemical test to show better reducing sugar is present

Answer 21

add a heated Benedix reagent to the sample and observe the colour
if the sample turns yellow red orange a reducing sugar is present

Question 22

True or false?

starch glycogen deoxy both contain only the elements carbon hydrogen and oxygen

Answer 22

true

Question 23

what is DNA Helicase made from?

Answer 23

amino acids

Answer 24

.