Biochem

Question 1

What kind of bonding is shown in the phospholipid bilayer

Answer 1

Hydrophobic forces between long hydrophobic chains in midlayer

Question 2

What is acylation

Answer 2

Addition of a group containing a carbon double bonded to oxidation

Question 3

What type of reaction is condensation

Answer 3

Anabolic (2 smaller molecules are ‘built up’ to a larger molecule)

Question 4

What type of reaction is hydrolysis

Answer 4

Catabolic (larger molecule broken down)

Question 5

What is the final oxidative stage of carbon

Answer 5

Carbon dioxide

Question 6

What is metabolism

Answer 6

Net oxidative process where carbon is fully reduced to an oxidised state

Question 7

Functions of biomolecules

Answer 7

Information storage
Structural
Energy generation
Energy/currency storage - atp
Communication - receptors, hormones etc

Question 8

What are the classes of biomolecules

Answer 8

Peptides and proteins
Lipids
Nucleic acids
Carbohydrates - saccharides

Question 9

How is energy stored within the cell

Answer 9

Through carbohydrates in the form of carbon chains

Question 10

What makes the glucose molecules a reducible target

Answer 10

The oxygen atom between carbon 1 and carbon 5

Question 11

How are disaccharides formed

Answer 11

Covalent bonds between c1 - c4 or c1-c2

Question 12

What is polymeric glucose

Answer 12

Glycogen - energy store

Question 13

Which carbon links form the polymer, glycogen?

Answer 13

C1-c6

Question 14

When is some energy unavailable to do work

Answer 14

When energy is transformed

Question 15

What is an exergonic reaction

Answer 15

If the free energy change is negative

Question 16

When can reactions occur spontaneously

Answer 16

If the change in free energy is negative

Question 17

What are examples of exergonic reactions

Answer 17

Energy left over from reaction can do work such as conversion of glycogen to glucose

Question 18

What are endergonic reactions

Answer 18

Free energy change is positive
Cannot occur spontaneously - need an input of energy

Question 19

What shape is a water molecule

Answer 19

Tetrahedral (lone pairs)

Question 20

What substances are hydrophilic

Answer 20

Ionic and polar (can dissolve in water)

Question 21

What is the isoelectric point of a molecule

Answer 21

The pH at which a molecule has no net charge

Question 22

How many pKa values do amino acids with no charge have

Answer 22

2 as they have 2 titratable groups

Question 23

How can proteins act as buffers

Answer 23

Several amino acid side chains can be ionised

Question 24

What happens to a protein if there is a change in pH

Answer 24

Can change ionisation of a protein which can lead to a change in structure therefore function

Question 25

How is hydrogen bonding promoted in biomolecules

Answer 25

Difference of EN of atoms in water create dipoles

Question 26

How can amphipathic molecules span polar and non-polar environments

Answer 26

Due to hydrophobic and hydrophilic domains

Question 27

Where do the unique buffering abilities of protein come from

Answer 27

Zwitterionic properties of amino acids

Question 28

How can changes in protein conformation arise

Answer 28

Redox interaction that affect the state of metal ion centres
Disulphide bridges
Salt bridging
Hydrophobic interactions
Electrostatic (polar?) interactions

Question 29

What strutcure of the protein is important to its function

Answer 29

Tertiary (peptide fold)

Question 30

What can changes in amino acid sequence lead to

Answer 30

Altering of function