Molecules Topic

Question 1

What type of energy can break hydrogen bond quickly?

Answer 1

Heat

Question 2

What is a polar molecule?

Answer 2

A molecule with a charged functional group i.e water
A.K.A Hydrophilic or “Water-loving” molecule

Question 3

What is a non-polar molecule?

Answer 3

A molecule that lacks a charged functional group - electronegativity is balanced across the molecule.
A.K.A Hydrophobic or “Water-hating” molecule

Question 4

What is electronegativity?

Answer 4

The tendency of an atom or functional group to attract electrons to itself

Question 5

In what kind of environment do most cellular reactions take place?

Answer 5

Aqueous solution

Question 6

What is a buffer?

Answer 6

A chemical that resists changes in pH

Question 7

How do buffers work?

Answer 7

They can act as both a base and an acid -
Acid by donating hydrogen ions to help neutralise an alkali solution
Base by mopping up hydrogen ions to neutralise an acidic solution

Question 8

What are examples of buffers?

Answer 8

phosphate ions, hydrogencarbonate ions, blood proteins (e.g albumin)

Question 9

Potassium ion + function

Answer 9

K+ , Maintains electrical gradients across cell membranes, important for nerve impulses.

Question 9

Potassium ion + function

Answer 9

K+ , Maintains electrical gradients across cell membranes, important for nerve impulses.

Question 10

Calcium ion + function

Answer 10

Ca+ , In plants calcium pectate is a major component of the middle lamella of cell walls. In animals main constituent of bones teeth and shells. It is needed for blood clotting and muscle contraction

Question 11

Magnesium ion + function

Answer 11

Mg+, Constituent of chlorophyll. It is the magnesium part of the chlorophyll molecule that is responsible for absorbing light energy

Question 12

Iron ion + function

Answer 12

Fe2+, Constituent of electron carriers in respiration. Forms part of haem group in respiratory pigments e.g haemoglobin

Question 13

Hydrogencarbonate ion + function

Answer 13

HCO3-, Component of haemoglobin and allows buffering of the blood (carbon dioxide forms acid in the blood)

Question 14

Phosphate ion + function

Answer 14

PO4(3-), A component of cell membranes in the form of phospholipids. Phosphates are a major constituent of bone and teeth. Component of ATP. DNA is made up of nucleotides, which in turn have a phosphate component.

Question 15

What are the four main macros?

Answer 15

Carbs, Lipids, Protein and Nucleic Acids(!)

Question 16

What are carbohydrates?

Answer 16

Carbohydrates contain 3 elements - Carbon, Hydrogen and Oxygen. They are given the general formula (CH₂O)ₙ

Question 17

What is the general formula for Carbohydrates?

Answer 17

(CH₂O)ₙ

Question 18

What are the 3 main types of carbohydrate?

Answer 18

Monosaccharides, Disaccharides, Polysaccharides

Question 19

What is a monosaccharide? Give three examples.

Answer 19

Monosaccharides are the basic carbohydrate monomers i.e single (simple) sugars. Monosaccharides are sweet, soluble and crystalline with relatively small molecules.
Glucose
Fructose
Galactose

Question 20

What is a Disaccharide?

Answer 20

Disaccharides are double sugars formed from 2 monosaccharide monomers

Question 21

What is a Polysaccharide?

Answer 21

Polysaccharides are complex molecules usually containing MANY monosaccharide monomers.

Question 22

Define “monomer”

Answer 22

Monomers are small molecules, mostly organic, that can join with other similar molecules to form very large molecules, or polymers. All monomers have the capacity to form chemical bonds to at least two other monomer molecules.