Chemistry of Life

Question 1

Glucose formula

Answer 1

C6H12O6

Question 2

Primary stimulant for breathing

Answer 2

CO2

Question 3

Inorganic compounds

Answer 3

Usually lack carbon, simple structures, held together by ionic or covalent bonds e.g. salts, water, acids and bases

Question 4

Organic compounds

Answer 4

Usually contain carbon, hydrogen and are always held together by covalent bonds

Question 5

Water

Answer 5

makes up 55-60% of our body mass

excellent solvent, participates in chemical reactions, absorbs and releases energy slowly

Question 6

Salts

Answer 6

dissociate into cations and anions

Question 7

Acids

Answer 7

dissociate into H+ ions when dissolved in water

Question 8

Bases

Answer 8

dissociate into OH- ions when dissolved in water

Question 9

Acid-base balance

Answer 9

must be balanced to ensure homeostasis.
chemical reactions in body are sensitive to slightest change in pH and any departure from narrow lips disrupts functions and can cause disease
CO2 + H20 –> H2CO3

Question 10

Acidotic

Answer 10

when body fluids contain too much acid
Metabolism - too much acid in kidneys. Due to diabetes, loss of sodium bicarbonate, too much lactic acid or kidneys are unable to excrete acid
Respiratory - too much CO2. Due to asthma, injury to chest, obesity, alcohol overuse, muscle weakness or problems with nervous system

Question 11

Buffer Systems

Answer 11

chemical compounds that act quickly to temporarily bind H+, removing the highly reactive, excess H+ from solution but not from the body

Question 12

Monosaccharides

Answer 12

organic
(CH2O)n
simple sugars like glucose

Question 13

Dissacharides

Answer 13

organic

simple sugars - two monosaccharides linked together

Question 14

Polysaccharides

Answer 14

large, complex carbohydrates that contain 10s or 100s of monosaccharides joined through dehydration synthesis

Question 15

Lipids

Answer 15

hydrophobic, mainly non polar
Hydrocarbons with mostly non polar C-C or C-H bonds
Fat molecules consists of glycerol and a fatty acid joined through an ester bond which releases three water molecules
Triglycerides, phospholipids, steroids and fat-soluble lipids

Question 16

Triglycerides

Answer 16

fats and oils

Question 17

Phospholipids

Answer 17

lipids that contain phosphorus

major component of all cell membranes

Question 18

Fat-soluble lipids

Answer 18

Vitamins A, D, E, K

Question 19

Glycolytic pathway equation

Answer 19

Glucose –> G3P –> Pyruvate –> Tricarboxylic acid cycle or lactic acid

Question 20

Steroids

Answer 20

can act as hormones in the body

Question 21

Proteins

Answer 21

sourced from large complex structure, broken down into amino acids

Question 22

ATP

Answer 22

Adenosine Triphosphate

Question 23

Carbonic acid bicarbonate buffer system

Answer 23

Cellular respiration produces CO2 as a waste product which is immediately converted to a bicarbonate ion in the blood. On reaching the lungs, it is converted back and released as CO2.

Question 24

Phosphate buffer system

Answer 24

operates in internal fluids of all cells.
consists of dihydrogen phosphate ions as donor and hydrogen phosphate ions as acceptor which neutralise any excess hydrogen or hydroxide ions.

Question 25

Protein buffer system

Answer 25

helps maintain acidity in and around the cells. Haemoglobin makes an excellent buffer by binding to small amounts of acid in the blood before they can alter the pH.

Question 26

How does haemoglobin bind?

Answer 26

As the partial pressure of oxygen increases, the more haemoglobin it can bind to. Haemoglobin can bind to a maximum of four oxygen molecules. When acidity of the blood increases, haemoglobin’s affinity for oxygen decreases and oxygen dissociates from the haemoglobin. As hydrogen ions enter, haemoglobin releases oxygen - this is called compensation

Question 27

Use of electrolytes in the body

Answer 27

They regulate nerve and muscle function, hydrate the body, balance blood acidity and pressure, and help rebuild damaged tissue.

Question 28

Examples of electrolytes

Answer 28

sodium, potassium, calcium, magnesium, bicarbonate