Lecture 4

Question 1

carbohydrates

Answer 1

• molecules in which carbon is flanked by hydrogen and hydroxyl groups
  ( H — C —- OH)
• contain a carbonyl group, several OH functional groups and many high energy C-H bonds

Question 2

generalized chemical formula of carbohydrates

Answer 2

(CH2O)n

Question 3

why do cells use as an energy source?

Answer 3

glucose (monosaccharide)

Question 4

2 forms of glucose

Answer 4

• linear
• rings

Question 5

why do cells do with glucose during cellular respiration?

Answer 5

• they oxidize glucose molecules to convert the stored energy to a form that can be readiliy used for cell work

Question 6

why is glucose oxidized ?

Answer 6

so an organelle, the mitochondria, can make ATP

Question 7

covalent bonds of glucose monomers

Answer 7

glycosidic linkagges

Question 8

2 types of glycosidic linkage

Answer 8

beta and alpha glucose chains

Question 9

alpha glucose chains (def)

Answer 9

• store chemic energy

Question 10

type of alpha glucose chains

Answer 10

• starch (plant energy storage)
• glycogen (animal energy storage: liver & muscles)

Question 11

beta glucose chain (def)

Answer 11

• form fibrious structures
• straight chains held by many h bonds
• highly packed, difficult to hydrolyze

Question 12

type of beta glucose chains

Answer 12

• cellulose (plants)
• chitin (fungus & insects)
• peptidoglycan (bacteria)

Question 13

different types of protein

Answer 13

• enzymes
• antibodies
• motor proteins and contractile proteins
• signalling molecules
• structural molecules
• transport molecules

Question 14

enzymes

Answer 14

• protein catalysts
• speed up chemical reactions

Question 15

antibodies

Answer 15

• these are protein that protect the body from pathogens

Question 16

motor proteins

Answer 16

• can move molecules around inside of the cell

Question 17

contractile proteins

Answer 17

contract muscles in animals allowing them to move

Question 18

signalling molecules

Answer 18

• cells can communicate by sending protein signals from one cell to the other
• often called hormones

Question 19

structural molecules

Answer 19

gives cell a shape

Question 20

transport molecules

Answer 20

move molecules in and out of the cell

Question 21

proteins

Answer 21

• chains of amino acids

Question 22

amino acids

Answer 22

• have carboxyl and amino groups
• they function as both acid and base
• side chain varies from on amino acid to another
• 20 different kinds

Question 23

bons between amino acid

Answer 23

peptide bonds

Question 24

chain of peptide bons

Answer 24

polypeptide chain

Question 25

r groups

Answer 25

differ in size, shape, reactivity and interactions with water

Question 26

nonpolar r groups

Answer 26

• hydrophobic
• do not readily dissolve in water
• will sooner aggregate with other hydrophobic molecules

Question 27

polar r groups

Answer 27

• hydrophilic
• form h-bonds and readily dissolve in water

Question 28

primary structure of a protein

Answer 28

linear squence of amino acids/

Question 29

secondary structure

Answer 29

• side groups within the amino acid chain interact causing the protein to fold into secondy structures
• determined by the primary structure
• h-bonds form between carbonyl groups, making them bend

Question 30

what can one change in amino acid do?

Answer 30

• one change of amino acid can have drastic effects

Question 31

secondary structure patterns

Answer 31

• alpha helix (coil)
• beta pleated sheet (accordion)

Question 32

tertiary structure

Answer 32

• result of interactions between r-groups in a polypeptide chain or between r-groups and peptide backbone

Question 33

interactions between r-groups

Answer 33

• h-bonds
• hydrophobic interactions
• van der waals interactions
• convalent disulfide bonds
• ionic bons

Question 34

quaternary structure

Answer 34

• several polypeptide chains can interact to form one protein
• produce by the bonding of two or more polypeptid subunits

Question 35

protein structure

Answer 35

• hierarchical
• quaternary is based on tertiary, which is based on secondary
• all 3 higher levels are based on the primary structure

Question 36

folding in proteins

Answer 36

• proteins fold spontaneously when produced in a cell
• fold into energetically stable form

Question 37

protein unfolding

Answer 37

• stable form disrupted by high temperatures or low exposure to pH
• proteins unfolds = denatures

Question 38

molecular chaperones

Answer 38

proteins that fold proteins