Building Blocks of Biology

Question 1

What is a carbohydrate?

Answer 1

A molecule that contains carbon, hydrogen and oxygen

Question 2

4 types of saccharide

Answer 2

1= monosaccharide
2=disaccharide
3-10=oligosaccharide
>10= polysaccharide

Question 3

Functions of monosaccharides

Answer 3

Cellular energy
Build nucleic acids

Question 4

Chemical formula of most monosaccharides

Answer 4

(CH2O)n n = 3,5 or 6

Question 5

What is a structural isomer?

Answer 5

Same chemical formula but atoms arranged differently

Question 6

What are the monosaccharides and where are they found?

Answer 6

Glucose- fruit and veg
Fructose- highest concn in carrots
Galactose- dairy products, avocados

Question 7

What is a condensation reaction?

Answer 7

Chemical reaction where we lose water
Disaccharides are formed when 2 monosaccharides are bonded together (glycosidic bond between 2 hydroxyl groups)

Question 8

What are all the disaccharides?

Answer 8

Maltose= glucose + glucose
Sucrose= Glucose + fructose
Lactose = Glucose + galactose

Question 9

What is a lipid?

Answer 9

Fatty, waxy or oily in composition and mostly insoluble in water

Question 10

What are the functions of lipids?

Answer 10

Protection/ insulation
Neuron myelination
Absorption of fat soluble vitamins (A,D,E,K)
Hormone production
Cell membranes

Question 11

What is a fatty acid?

Answer 11

These are organic chains with a carboxyl group

Question 12

3 types of lipid

Answer 12

Triglycerides
Phospholipids
Sterols

Question 13

What is a triglceride?

Answer 13

Glycerol with 3 bonded fatty acids (carboxyl to hydroxyl) - body fat

Question 14

Difference between saturated and unsaturated?

Answer 14

Saturated all C-C bonds
Unsaturated may contain C=C
Double bonds can be cis (attached to same side) or trans (opposite side) geometry

Question 15

What is a phospholipid?

Answer 15

Has a glycerol with 2 fatty acid chains and a phosphate head

Question 16

What is the difference between hydrophobic and hydrophilic?

Answer 16

Hydrophobic is against water
Hydrophilic is attracted to water

Question 17

What is a sterol?

Answer 17

Cyclic organic compounds found in grains, nuts, fruits and veg

Question 18

What is the function of cholesterol?

Answer 18

Synthesis of e.g. vit D, bile, sex hormones
Cell membrane structure
Known for role in heart disease

Question 19

What is the function of proteinogenic amino acids and how many are there?

Answer 19

Vital in the formation enzymes, antibodies, hormones, structural proteins and receptors

20 are coded for by DNA

Question 19

What is a protein?

Answer 19

Made up of a long chain of amino acids joined by peptide bonds

Question 20

How are proteins written?

Answer 20

From the N to the C terminus

Question 21

What is the primary structure?

Answer 21

The amino acid sequence, from N- to C- terminus

Question 22

What is the secondary structure?

Answer 22

Local structural features

Question 23

What is an alpha helix?

Answer 23

Formed between carboxyl and amine groups
Each C=O forms a hydrogen bond with the amide hydrogen

Question 24

What is a beta pleated sheet?

Answer 24

The backbone is able to form hydrogen bonds between each segment as the angular conformation of the peptide causes a zig zag.
Can be parallel or antiparallel

Question 25

What is the tertiary structure?

Answer 25

Long amino acid chain folds itself - 3D
Multiple bonds and interactions

Question 25

What is the quaternary structure?

Answer 25

A protein made up of a number of subunits e.g. haemoglobin
Arrangement due to intermolecular forces

Question 26

What are the covalent and non covalent interactions that can occur in protein structure?

Answer 26

Electrostatic interaction
Pi Pi stacking - favourable
Hydrophobic
Hydrogen bonding
Disulfide bridges - cystine