Topic 1

Question 1

What is the bond that is formed during the condensation reaction between 2 monosaccharides?

Answer 1

A glycosidic bond

Question 2

What are carbohydrates?

Answer 2

Carbs are molecules which consist only of carbon, hydrogen and oxygen

Question 3

What is starch ?

Answer 3

Starch is what plants store as excess glucose. When plants require glucose for respiration/energy starch is broken down into glucose

Question 4

Describe the structure of starch

Answer 4

Made out of amylose (long unbranched chain of a-glucose molecules. Due to its specific glycosidic bonding shape becomes coiled and very compact) and amylopectin (long branched chain of a-glucose molecules-lots of side branches)

Question 5

Describe the test for starch in basic terms

Answer 5

Add test sample to iodine solution (potassium iodine solution) if solution turns blue/black then starch is present

Question 6

Triglycerides are used as what ?

Answer 6

Energy storage molecules

Question 7

What do the hydrocarbon tails of triglycerides contain which is useful for us ?

Answer 7

Chemical energy

Question 8

Lipids contain how much more energy than carbohydrates?

Answer 8

Double

Question 9

Are triglycerides insoluble or soluble?

Answer 9

Insoluble, don’t affect water potential

Question 10

How do triglycerides act in cells ?

Answer 10

They clump together as insoluble droplets, the tails face inwards and the heads face out.

Question 11

What do phospholipids do ?

Answer 11

Make up the bilayer of the cell membrane meaning they control what enters and leaves the cell

Question 12

What do phospholipids form ?

Answer 12

A double layer, heads outside and tails inside forming a barrier against water soluble substances

Question 13

What are the monomers of protein ?

Answer 13

Amino Acids

Question 14

How is a polypeptide formed?

Answer 14

Formed by more than two amino acids joining together

Question 15

How are proteins made up ?

Answer 15

Made up of one or more polypeptides

Question 16

How are proteins made up ?

Answer 16

Made up of one or more polypeptides

Question 17

What is the name of the bond formed between 2 amino acids

Answer 17

Peptide Bond

Question 18

Describe the primary structure of a protein

Answer 18

The sequence of amino acids in the polypeptide chain

Question 19

Describe the secondary structure of a protein

Answer 19

Hydrogen bonds form between the amino acids in the chain, making it Coil into an alpha helix or beta pleated sheet

Question 20

Describe the tertiary structure of a protein

Answer 20

The chain is coiled further and more hydrogen and ionic bonds form

Question 21

Describe the Quaternary structure of a protein

Answer 21

Made of several different polypeptide chains held together by different bonds

Question 22

When do disulphide bridges form ?

Answer 22

Whenever 2 molecules of cysteine coke close together

Question 23

What are enzymes and what do they do ?

Answer 23

Enzymes are biological catalysts. They catalyse metabolic reactions at a cellular level and across the whole organism. They speed up reactions

Question 24

What can enzymes affect ?

Answer 24

Structures in an organism E.g collagen production and functions E.g respiration

Question 25

What makes each enzyme different?

Answer 25

Their active site which has a specific shape

Question 26

How are enzymes specific?

Answer 26

Their tertiary structure

Question 27

What is the lock and key model ?

Answer 27

Where the substrate fits exactly into the enzyme

Question 28

What is the induced fit model ?

Answer 28

Where the substrate fits into the enzyme then the enzyme changes it’s shape slightly to lock the substrate even tighter into itself

Question 29

What is it called when an enzyme and substrate are joined together?

Answer 29

Enzyme- substrate complex

Question 30

What happens if the tertiary structure of an enzyme is altered?

Answer 30

The shape of the active site will change, meaning the substrate won’t be able to fit so the enzyme is unable to carry out its function of catalysing the substrate

Question 31

What determines the primary structure of a protein?

Answer 31

A gene

Question 32

Why does temperature have such a large impact on enzyme activity?

Answer 32

Because each enzyme has its own optimum temp, anything before that will decrease the rate of reaction and anything above will result in bonds breaking and the enzymes becoming denatured

Question 33

What are the 2 main groups of lipids ?

Answer 33

Triglycerides and Phospholipids

Question 34

Name the type of chemical bond that joins the 2 monomers to form maltose

Answer 34

A glycosidic bond formed by a condensation reaction

Question 35

Similarity between lactose and lactulose

Answer 35

Both Disaccharide and Both have a glycosidic bond

Question 36

Difference between lactose and lactulose

Answer 36

Lactose contains glucose but lactulose contains galactose

Question 37

Name the main biological molecule in the cell wall

Answer 37

Murine/ Glycoprotein

Question 38

What is a short chain of amino acids know as ?

Answer 38

Peptide chain or polypeptide

Question 39

What does a molecule of a fatty acid consist of ?

Answer 39

A molecule of a fatty acid consists of a hydrocarbon chain and a carboxyl group (-COOH)

Question 40

What are the basic functions of lipids ?

Answer 40

Energy source Insulation Protection Structural Molecules

Question 41

What is a covalent bond?

Answer 41

The bond formed between atoms that share electrons

Question 42

What is a covalent bond?

Answer 42

The bond formed between atoms that share electrons

Question 43

Why is water described as a polar molecule?

Answer 43

Because the electrons that are shared in the covalent bond between oxygen and hydrogen are unevenly distributed

Question 44

Describe the primary structure of all proteins

Answer 44

The primary structure is the sequence of amino acids in a polypeptide chain joined by peptide bonds

Question 45

What is universal (genetic code) ?

Answer 45

The same codon/triplet that always codes for the same amino acid

Question 46

What is non-overlapping (genetic code) ?

Answer 46

Each base is only part of one triplet/codon. They do not overlap

Question 47

What is degenerate (genetic code) ?

Answer 47

More than one codon/triplet codes for each amino acid

Question 48

Describe 2 differences between the structure of a Triglyceride and a phospholipid

Answer 48

A Triglyceride has 3 fatty acids and 3 ester bonds rather than 2 and it has no phosphate group unlike a phospholipid

Question 49

Describe 2 differences between the structure of a Triglyceride and a phospholipid

Answer 49

A Triglyceride has 3 fatty acids and 3 ester bonds rather than 2 and it has no phosphate group unlike a phospholipid

Question 50

Explain why phospholipids Can form a bilayer but Triglycerides can’t

Answer 50

Because phospholipids are both hydrophobic/hydrophilic. But Triglycerides are only hydrophobic. And a hydrophilic/phosphate group attracts water to both sides of bilayer

Question 51

State one role of a helper T cell

Answer 51

Stimulating phagocytes

Question 52

Describe the primary structure of all proteins

Answer 52

The primary structure is the sequence of amino acids in the polypeptide chain joined by peptide bonds

Question 53

Define universal (genetic code)

Answer 53

The same codon/triplet always codes for the same amino acid

Question 54

Define non-overlapping (genetic code)

Answer 54

Each base is only part of one