Carbohydrates

Question 1

What are carbs and where do they come from?

Answer 1

Made from plants via photosynthesis in form of glucose.

Question 2

Explain monosaccharides.

Answer 2

Smallest form of carbs. They are either aldehyde or ketones that have 2+ hydroxyl groups.

Question 3

What is dihydroxyacetone?

Answer 3

Smallest monosaccharide. Ketose used in sunless tanning agent.

Question 4

What is D-glyceraldhyde?

Answer 4

Smallest monosaccharide. Aldose. Glucose metabolite during respiration.

Question 5

What is an isomer?

Answer 5

Same molecular formula but different structure

Question 6

Two types of isomers.

Answer 6

Constitutional and stereoisomers

Question 7

What are constitutional isomers?

Answer 7

Different in attachment of atoms. Same molecular formula but different arrangement of atoms.

Question 8

What are stereoisomer and name two types.

Answer 8

Atoms connected in the same order but different spatial arrangement.
Enantiomers and diastereoisomer.

Question 9

What are enantiomers?

Answer 9

Non-superimposable mirror images.

Question 10

What are diastereoisomers and give two types.

Answer 10

Isomers that are not mirror images.
Epimers and anomers.

Question 11

What are epimers?

Answer 11

Differ at one of several asymmetric carbon atom.

Question 12

What are anomers?

Answer 12

Isomers that different at a new asymmetric carbon atom formed on ring closure.

Question 13

What is a disaccharide?

Answer 13

Two monomers covalently bonded together by an o-glycosidic bond. End can revert into linear form and act as reducing sugar.

Question 14

What monomers make maltose and where is it found?

Answer 14

Two glucose. Found in malt, corn syrup.

Question 15

What monomers make sucrose and where is it found in?

Answer 15

Glucose and fructose. Sugar, sugar cane, sugar beet.

Question 16

What monomers make lactose and where is it found in?

Answer 16

Galactose and glucose. In dairy.

Question 17

Explain how lactose intolerance is caused.

Answer 17

Lack of lactase causes lactose to pass into large intestine. H.conc. Of lactose causes h.osmolarity in large intestine stopping the water from being absorbed into blood leading to watery stool. Fermentation of lactose by bacteria causes production of carbon dioxide causing bloating.

Question 18

What is a polysaccharide?

Answer 18

Most carbs in nature found as polysaccharide or glycans. Many monomers joined together.

Question 19

Name two forms of polysaccharides.

Answer 19

Homopolysaccharides and heteropolusaccharides.

Question 20

In what form is glucose stored in during photosynthesis?

Answer 20

Starch, broken down into glucose monosaccharides.

Question 21

Name two types of starch.

Answer 21

Amylose and amylopectin

Question 22

Describe amylose.

Answer 22

Long chain of alpha 1.4 linked glucose monomers.

Question 23

Describe amylopectin.

Answer 23

Chain of monomers with branches. Alpha 1.6 linked glucose form branches.

Question 24

What is the energy store in animals called?

Answer 24

Glycogen.

Question 25

What is the energy store in animals called?

Answer 25

Glycogen.

Answer 26

Repeating monomers of glucose and has frequent branching of alpha 1.6 linked glucose molecules. Less soluble and doesn’t contribute to osmolarity. Soluble.

Question 27

What is the energy store in plants?

Answer 27

Cellulose.

Question 28

Describe cellulose.

Answer 28

Tough, fibrous, water insoluble. Linear chain of beta glucose monomers. 1.4 glycosidic bonds. Resistant to digestion.

Question 29

Example of heteropolysaccharide.

Answer 29

Glycosaminoglycans are I branched heteropolysaccharide, made of repeating disaccharide units. Rich in ECM.

Question 30

How is glucosaminoglycans is made.

Answer 30

Activating monomeric sugar, transfer across membrane, condense activated sugars into polysaccharids, add sulphate. All steps requires enzymes.

Question 31

What are proteoglycans?

Answer 31

Protein with specific sulphate glycosaminoglycans. Attached outside of PM and ECM. abundant in connective tissue. For adhesion, recognition, transfers between cells and ECM.

Question 32

What are glucoproteins?

Answer 32

Attachment carbs. Functions: enzyme, transport, receptors, hormones, and structural proteins.

Question 33

Are amino acids and carbs under genetic control?

Answer 33

Amino acids yes carbs no.

Question 34

What are lectins?

Answer 34

Proteins bind to carbs that allow glycoproteins to fulfil properties. Eg. Leukocytes migrate along blood vessel to find and destroy bacteria. During this endothelium cells will express a lectin called p-selectin which binds to oligosaccharides on glycoproteins expressed on leukocytes surface. This slows leukocytes down and through interaction with further lectin show the way to the infected site.