Week 3 - Bio building blocks

Question 1

Lactose intolerance is a common condition involving impaired ability to digest the sugar lactose. What is the cause? What symptoms occur and why? How can it be treated?

Answer 1

Congenital: your genetic make up causes you to have less lactase than usual
Gastroenteritis: can strip the intestines of lactase for a few weeks
Parasitic infection: this can temporarily reduce lactase levels
Iron deficiency: ca interfere with with lactose digestion and absorption

Treated: avoid lactose, eat food where lactase has already been degraded

Question 2

3 major biological roles of carbohydrates.

Answer 2

1. ) source of stored energy
2. )Transport stored energy with complex organisms
3. )Serve as a carbon skeleton that can be rearranged to form new molecules

Question 3

What does hemoglobin do?

Answer 3

Binds O2
the 4 subunits shift their relative position slightly, changing quaternary structure
ionic bonds are broken, exposing buried side chains that enhance the binding of additional O2 molecules

The quaternary structure changes again when hemoglobin releases O2 molecules to the cells of the body

Question 4

examples of a monosaccharide?

Answer 4

fructose, glucose, ribose, galactose

Question 5

examples of disaccharides?

Answer 5

sucrose, lactose

Question 6

examples of polysaccharides?

Answer 6

starch, cellulose, glycogen

Question 7

epimer?

Answer 7

stereoisomers that differ in position of the hydroxyl group at only one C
eg, D glucose and D galactose

Question 8

what are oligosaccharides bonded to?

Answer 8

covalently bonded to proteins and lipids on the outer cell surface.
serve as a recognition site
eg, ABO blood types

Question 9

why is starch less compact than glycogen?

Answer 9

branching limits the number of hydrogen bonds that can form in starch molecules

Question 10

different functions of lipids?

Answer 10

thermal insulation
lipid coating around nerves provide electrical insulation
oil on skin repels water

Question 11

what is the melting point of unsaturated FA?

Answer 11

low, liquid at room temperature

Question 12

what are carotenoids?

Answer 12

light absorbing pigments

Question 13

what do proteins consist of?

Answer 13

linear covalently bonded amino acids

Question 14

how is a peptide bond formed from the backbone of a protein?

Answer 14

carboxyl group of one amino acid reacts with an amine group of another by condensation reaction.

Question 15

all the bonds in tertiary structure?

Answer 15

hydrogen bonds 
VDW interactions
hydrophobic interactions 
ionic bonds
disulfide bridges

Question 16

conditions that affect secondary and tertiary structure?

Answer 16

high temp
high pH
high concentration of polar molecules
non polar substances

Question 17

sickle cell anemia?

Answer 17

single amino acid change in primary structure results in structure change for 2,3,4.
this results in reduced capacity to carry oxygen and sickle cell disease
blocks blood flow

Question 18

DNA?

Answer 18

macromolecule that encodes hereditary info and passes it from generation to generation

Question 19

RNA?

Answer 19

information encoded in DNA is used to specify the amino acid sequences of proteins

Question 20

what connect nucleotides?

Answer 20

phosphodiester bonds

Question 21

how are the DNA strands kept together?

Answer 21

hydrogen bonds