Biomolecules

Question 1

What is a biomolecule?

Answer 1

Any organic molecule that is an essential part of a living organism.

Question 2

What is a lipid?

Answer 2

A lipid is an ester.

They are a mixture of Glycerides but most are triglycerides.

Question 3

What is the reaction that results in a triglyceride being formed? what is the chemical equation?

Answer 3

Condensation reaction.

+ 3fatty acid = triglyceride + 3waters

Question 4

what is the difference between saturated fats, mono-unsaturated fats and polyunsaturated fats?

Answer 4

saturated fats have no double bonds,

mono-unsaturated fats have one double bond

polyunsaturated fats have two or more double bonds, there is usually two.

Question 5

fats have a higher ______ point and is therefore solid. they have greater________ forces between the fat molecules. Fat is _______.

Oils have a lower ________ point and is therefore a ______. they have fewer ______ than the fats do and therefore oils are ______.

Answer 5

fats have a higher** boiling** point and is therefore solid. they have greater** despersion** forces between the fat molecules. Fat is** saturated**.

Oils have a lower boiling point and is therefore a liquid . they have fewer despersion forces than the fats do and therefore oils are unsaturated.

Question 6

what does the double bond equivalence determine?

Answer 6

how many double bonds are present without needing to draw the structure of the molecule.

DBE= C_nH/2 + 1

Question 7

what is a surface acting agent?

Answer 7

a substance that contains a polar and non-polar part to make substances that cannot dissolve in a solution, dissolvable.

Question 8

Why are proteins important biomolecules?

Answer 8

they form a large portion of structural material for humans and animals alike.

They have roles as enzymes, hormones, and antibodies.

Haemoglobin (carries oxygen in the blood) is a protien.

They are a source of energy.

Question 9

What does a protien structure always contain?

Answer 9

Carbon

Hydrogen

Oxygen

Nitrogen

sometimes sulfur

CHONS

Question 10

Are amino acids soluble in water? if so why?

Answer 10

Yes they are and because of the polarity of both the groups.

Question 11

What is an R-group?

Answer 11

it is a side chain.

Question 12

In human nitrition, some ___ amino acids make up all the ______ found in the body. The human body manufactures ___ of these that are known as being ___________ while ____ known as being _____ must be part of the human diet.

Answer 12

In human nitrition, some 20 amino acids make up all the proteins found in the body. The human body manufactures 11 of these that are known as being unessential while 9 known as being essential must be part of the human diet.

Question 13

what is a zwitterion?

Answer 13

an amino acid at neutral pH when the proton on the caroboxyl group is transferred tothe amino group as ⁺H₃NCH₂COO^-

Question 14

What happens to the amino acid in acidic conditions?

Answer 14

⁺H₃N-CHR-COO^- _(aq) + H₃O⁺_(aq)

=

⁺H₃N-CHR-COOH_(aq) + H₂O_(l)

Question 15

What happens to amino acids in alkaline conditions?

Answer 15

⁺H₃N-CHR-COO^-_(aq) + OH^-_(aq)

=

H₂N-CHR-COO^-_(aq) + H₂O _(l)

Question 16

what happens when two amino acids react?

Answer 16

they expell a molecule of water in the condensation reaction and a peptide link is formed. the product of two amino acids reacting is a dipeptited.

Question 17

considering the molecular shape of a protien determines its function. what are the different molecular shapes for protiens?

Answer 17

primary structure - the order of the amino acids along the chain. they are covalently bonded.

Secondary structure - is the spiralling and pleating caused by hydrogen bonding that occurs between the -C=O and -N-H groups within the chain.

Tertiary structure-is the interaction between the R-groups. it causes folding and bending determining whether the protein is fibrous or globular. It may involve H-bonding, dipole-dipole bonding, covalent or ionic bonding depending on the polarity of the side group. the -SH group in cysteine can form disulfide links, -C-S-S-C-, between neighbouring groups in the presence of an oxidant.

Question 18

What is denaturation?

Answer 18

the disruption of the tertiary and secondary structures of a protien through heating or a change in pH.

Denaturation makes some foods more digestible.

Question 19

In denaturation why is the primary structure of a protien not effected?

Answer 19

its not effected because the covalent bonding holding the amino acids together is relatively strong.

Question 20

What is coagulation and when does it occur?

Answer 20

it occurs after denaturation and it is the process of changing a liquid into a thickened mass.

Example: Egg white going from being uncooked to being cooked. it goes from being a liquid to a thickened white mass