week 1-3 (chemical basis of life, what is life, the cell)

Question 1

list the 5 characteristics that define life

Answer 1

Homeostasis
Organisation
Metabolism
Evolution
Reproduction

Question 2

name the three domains of life

Answer 2

bacteria
archaea
eukarya

Question 3

name the three macromolecules (built from multiple repeating units added together)

Answer 3

carbohydrates
lipids
nucleic acids

Question 4

other word for fats

Answer 4

triglyceride

Question 5

fats are a kind of polymer. name the two types of smaller molecules which build up fats.

Answer 5

glycerol
3 fatty acid tails

Question 6

define and compare unsaturated vs. saturated fatty acids

Answer 6

unsaturated fatty acids have all of its carbon atoms bonded with hydrogen atoms. this keeps the fatty acid straight.
unsaturated fatty acids lack hydrogens, so form a double bond with a carbon. this forms a kink.

Question 7

define steroids

Answer 7

steroids are a type of lipid characterised by four carbon rings.
cholesterol is found in animals. phytosterol is found in plants.

Question 8

describe the process of synthesising polymers.

Answer 8

via a dehydration process.
Monomers lose a H2O molecule, forming a vacant bond. specialised enzymes can be used to speed up this process.

Question 9

describe the process of breaking down of polymers

Answer 9

via hydrolysis
by adding a H2O molecule a bond is broken. Specialised enzymes can be used to speed up this process.

Question 10

what kind of linkages join monosaccharides to form disaccharides?

Answer 10

glycosidic linkage

Question 11

name two storage polysaccharides

Answer 11

starch
- plants store surplus starch as granules within chloroplasts and other plastids
glycogen
- glycogen is mainly stored in the liver and muscle cells
- hydrolysis of glycogen releases glucose when there is a need for glucose in the blood stream.

Question 12

name one structural polysaccharide

Answer 12

cellulose
- is a major component of the cell wall
- cellulose is also a polymer of glucose, but with a different glycosidic linkage

Question 13

what atoms are found in carbohydrates (in the name)

Answer 13

carbon
hydrogen
oxygen

Question 14

list the four classifications of the 20 amino acids and their interactions with water

Answer 14

non-polar = hydrophobic
polar = hydrophilic
acidic = hydrophilic, negatively charged
basic = hydrophilic, positively charged

Question 15

explain denaturation and renaturation

Answer 15

denaturation is when a proteins shape/polypeptide chain unfolds/coils. protein is now unable to perform its function.
renaturation is when a proteins unfolded polypeptide chain reforms into its original form, allowing the protein to perform its function once again.