Biological Molecules

Question 1

What is the general formula of carbohydrates?

Answer 1

(CH2O)n

Question 2

Name some small molecules (roughly 30 carbon atoms w a molecular weight of 100-1000)

Answer 2

Sugars, amino acids, nucleotides, lipids/fats

Question 3

Examples of large molecules (macromolecules)

Answer 3

Polysaccharides, proteins, nucleic acids

Question 4

Name the 2 types of monosaccharides and the difference between them

Answer 4

Ketone = ketose ( with = O in the middle)
Aldehyde = Aldose ( with = O on the end)

Question 5

Describe the structure of glucose

Answer 5

6 carbon atoms
D or L configuration ( depends on the C atom - whether its asymmetric or not )
Can exist in long chain or ring structure

Question 6

What is the difference between alpha and beta glucose

Answer 6

Beta- OH group on opposite sides of the carbon ( on c1 and c4)

Alpha - OH groups on the same side of c1 and c4

Question 7

Examples of some disaccharides

Answer 7

Sucrose = Galactose + Fructose

Lactose = Galactose + Glucose

Question 8

What happens when a disaccharide breaks apart

Answer 8

Condensation reaction releases water (breaking of 1-4 glycosidic bond)

Question 9

Examples of some polysaccharides

Answer 9

Cellulose (beta 1-4 glycosidic bonds)

Starch / Glycogen (alpha 1-4 glycosidic bonds)

Question 10

Describe the structure of glycogen

Answer 10

Made of Aldose

It’s a hexose

Very compact and branches for 1-6 glycosidic bonds

Question 11

What is an Oligosaccharide

Answer 11

Contains many different monosaccharides

E.g red blood cells

Question 12

Give an example of Oligosaccharides

Answer 12

Blood groups - differences in monosaccharides =
difference in structure =
difference in space and
difference in antibodies needed

Question 13

Describe the structure of an amino acid

Answer 13

Amine groups , R group and a carboxylic acid groups all around a central carbon atom

Question 14

What happens when 2 amino acids bond

Answer 14

Peptide and released water in a condensation reaction

Question 15

Name and describe the types of protein structure

Answer 15

Primary = covalent bonds forming polymers

Secondary = regular folded form in helixes or sheets

Tertiary = 3D structure

Quaternary = multiple different secondary structures together

Question 16

Name some other functions of amino acids (not making proteins)

Answer 16

They are the bases for which all hormones are made

Question 17

Describe the structure of a nucleotide

Answer 17

In RNA = phosphate, ribose sugar and base

In DNA = phosphate, deoxyribose sugar and base

Deoxyribose sugar has one fewer oxygen atom than ribose sugar

Question 18

What holds nucleotides together?

Answer 18

Phosphodiester bonds between the CH2 on the phosphate group of one nucleotide and the fourth carbon atom of the pentose sugar in the next nucleotide

Sugar phosphate backbone

Question 19

How many bonds between opposite bases

Answer 19

Three hydrogen bonds between guanine and cytosine

Two hydrogen bonds between adenine and thymine (or uracil)

Question 20

Where is the oxygen lost from in the deoxyribose

Answer 20

The 2nd carbon

Question 21

AMP

What does it stand for and what does it do?

Answer 21

Adenosine Monophosphate

One of the components of RNA & organic component of ATP

In certain vital metabolic processes - AMP combines w inorganic phosphate to form ADP then ATP

Question 22

Meaning of saturated, unsaturated cis and trans as relating to lipids

Answer 22

Saturated fatty acids = no double bonds ( in middle)

Unsaturated - trans = double bond & 2 H atoms next to double bond = on opposite sides

Unsaturated - cis = double bond & 2 H atoms next to double bond = on same side

Question 23

Describe the structure of a triglyceride

Answer 23

1 Glycerol bound to 3 fatty acid molecules by Ester bonds

Question 24

Describe the structure and function of a phospholipid

Answer 24

Consist of hydrophilic head and hydrophobic tail
Line up and arrange themselves in two parallel layers ( bilayer)

Selectively permeable (semi permeable), separates inside of cell from surroundings, can be broken down and used for energy , provide structure

Question 25

What is the relation between phospholipids and apoptosis

Answer 25

?

Phospholipid signalling

Question 26

What is cholesterol and what does it do?

Answer 26

Is a steroid and a type of lipid ( it is a fatty substance)

Essential structural component of animal cell membranes

Decreases fluidity and increases flexibility of the membrane

Reduces permeability for soluble molecules

Question 27

Name some important structure and function relationships

Answer 27

Proteins that denature or are mutated affect function

Starch and glucose are major energy sources for humans
Whereas we cannot digest cellulose

Single oxygen difference makes DNA much more stable than RNA

Question 28

Give some examples of single molecule diseases

Answer 28

Diabetes = absence of protein hormone (insulin ) leads to failure to regulate blood glucose

Sickle cell disease = one amino acid change in a globin chain causes haemoglobin to aggregate into polymers

Cystic fibrosis = absence of a membrane protein that transports chloride leads to altered properties of secretions