Carbohydrates

Question 1

What are carbohydrates ?

Answer 1

• Carbon-based molecules
• Rich in hydroxyl groups
• Used to generate energy with or without oxygen
• Important signalling molecules and structure

Question 2

What is lactose made out of ?

Answer 2

Galactose and glucose

Question 3

What is sucrose made out of ?

Answer 3

glucose and fructose

Question 4

What does the enzyme lactase do in the gut ?

Answer 4

cleaves the lactose molecules into its two subunits, glucose and galactose.

Question 5

What causes lactose intolerance ?

Answer 5

Due to a lack of the lactase enzyme therefore very common world wide but also moderately common in the uk population often developing through maturity. Around 30 percent of adults in Europe can’t drink milk

Question 6

What is maltose made out of and what’s it functions ?

Answer 6

Composed of two units of glucose joined with a 1- 4 glycosidic bond
Function is to breakdown product of starch

Question 7

What is the process of brewing beer starting with malting barley ?

Answer 7

-The process of brewing beer or lager starts with the production of malted barley
- Barely grains are soaked and heaped on floors where they warm up as they germinate. The germination process involves the breakdown of starch to sugars. After a few days when the first roots are produced, the germinated barley is dried which kills the seed and stops germination.
- Malted barley is then used in the first stage of brewing. The malt is mixed with hot water which extracts much of the sugars from the grains to produce wort, the liquid used to brew with using yeast

Question 8

what is starch composed of?

Answer 8

two polymers of glucose, amylose and amylopectin

Question 9

What is inulin ?

Answer 9

Is a polymer of fructose

Question 10

What is in the centre of a highly branched structure of glycogen and what does it serve to initiate ?

Answer 10

Has glycogenin, which serves to initiate glycogen biosynthesis

Question 11

What kind of enzyme is glycogenin - and what does the enzyme do to the glycogen structure ?

Answer 11

Is a glycosyltransferease enzyme which adds glucose molecules to the growing glycogen structure

Question 12

Where is glycogen found ?

Answer 12

In humans is found in all tissues but primarily in skeletal muscle and the liver, acting as a storage of glucose molecules which can be produced by glycogen degradation at short notice.

Question 13

Why is the breakdown of glycogen from the liver storage critical?

Answer 13

Critical to functional physiology and is critically controlled to maintain blood sugar levels.

Question 14

What is the first enzyme in the degradation pathway ?

Answer 14

Is glycogen phosphorylase

Question 15

Name 2 structural polysaccharides ?

Answer 15

Cellulose and chitin

Question 16

What do animals , plants and insects use as there structural units ?

Answer 16

Unlike animals who use calcium carbonate bones as their main structural units, organisms such as plants and insects use two different polymers of glucose as their main structural units.

Question 17

What is the structure of cellulose and its function ?

Answer 17

Cellulose is one of natures most abundant complexes and Is a polymer of glucose molecules joined by b(1-4) glycosidic bonds. This produces straight unbranched chains of glucose. It provides the major structure support in plant cell walls

Question 18

What are cellulose microfibrils ?

Answer 18

Chains of linear glucose polymers cross link into cellulose microfibrils which then align into cellulose microfibrils and hence cellulose fibres.

Question 19

How is cellulose made ?

Answer 19

cellulose is made in situ by a cellulose synthase enzyme complex which moves along underlying tracks in the cytoplasm laying down cellulose in the cell wall as it moves.

Question 20

What is cellulose broken down by and what does this mean about mammals guts ?

Answer 20

Cellulose enzymes break down cellulose into glucose but these enzymes only exist in bacteria and fungi and not mammals
Thus mammals need to relate symbiotically with such microorganisms within their guts to efficiently process cellulose.

Question 21

How do animals digest cellulose ?

Answer 21

Cows (ruminant) have anaerobic bacteria in their several stomachs that digest cellulose. They also chew the cud which extends the digestion time within the gut. One of the by products of this anaerobic metabolism is methane, a potent greenhouse gas which ruminants produce large amounts of

Question 22

What are termites and what do they use to digest cellulose ?

Answer 22

Are highly efficient at digesting cellulose in wood and use single celled organisms, called protists in their gut t carry out this digestion.

Question 23

What is chitin ?

Answer 23

Chitin is a polymer of glucose molecules each with one hydroxyl group replaced with an acetyl amine group. Hence chitin is a polymer of N-acetylglucosamine

Question 24

What makes chitin very tough and durable ?

Answer 24

There hydrogen bonds

Question 25

Why would carbohydrates be a better option for plastics ?

Answer 25

As they are biodegradable

Question 26

How can starch be used to make plastic ?

Answer 26

Starch derived bioplastic is made from potato starch and involves processing starch with other biopolymers to yield foldable plastic or film. Such film is now commonly available as biodegradable plastic