Key word associations

Question 1

Key words for DNA questions

Answer 1

• double stranded double helix
• anti parallel bonding
• hydrogen bonding between bases
• complmentary base pairing
• purine- pyrimidine bonding
• polymer
• sugar phosphate backbone

Question 2

Lipids as energy storage

Answer 2

• contain more energy per gram then carbohydrates
• contain less oxygen = more energy can be storeed in carbon-hydrogen bonds
• insoluble = can bes stored without affecting osmotic balance

Question 3

fats to avoid in the diet

Answer 3

• increase LDL fats (Low density lipoproteins) and decrease HDL (high density lipoproteins)
• trans fats
  => They increase blood cholesterol which could eventually cause coronary heart disease

Question 4

Cis vs trans

Answer 4

Both
* unsaturated

Cis
* lower m.p & b.p
* Hydrogen on same side
* in animals
* healthier

Trans
* in plants
* hydrogen on opposite side
* unhealthy
* have a kink

Question 5

Lipids

Answer 5

importance
* long term energy storage as they release high amount per gram
* insoluble = do not add excessive mass
* insulation for warmth
* phospholipid bilyaer for transport
* act as a shock absorber to protect organs
* needed for hormone regulation/production

detrimental effects
* trans fat raise low density lipoproteins and lower HDL = increase cholesterol
* high density cholesterol is linken to CHD

Question 6

Cellulose structure & function

Answer 6

• forms straight chains because beta glucose molecules are orientated alternately with 1,4 linkages
• straight chains = structural support
• hydrogen bonds between polymers form microfibrils
• cellulose microfibrils have high tensile strength = strong cell wall
• strong cell wall = no burst under high osmotic pressure

Question 7

Glycogen structure & function

Answer 7

• cruved twisted structure of alpha glucose molecules
• compact & branched = efficient storage + a lot
• branched = quickly released for respiration
• does not have a fixed size so glucose molecules can be put on or taken off

Question 8

Denaturation process

Answer 8

1. temp. increases = more kinetic energy
2. more successful collisions & ESC = rate of reaction increases up to optimum
3. after optimum = enzyme molecules vibrate = too much = break H Bonds
4. active site changes shape
5. no more ESC