chapter 3-6: biomolecules

Question 1

carbohydrates

Answer 1

• polymers of simple sugars (monosaccharides)
• store energy, provide structure, cell identity markers, immediate energy source, extracellular structural elements
• identified by terms saccharide or glyco

Question 2

monosaccharides

Answer 2

smallest sugars, can be ringed or linear, location and presence of OH groups indicate type

Question 3

how are monosaccharides joined to build complex carbohydrates?

Answer 3

glycosidic bonds (covalent)

Question 4

linear monomer bonding pattern

Answer 4

B-1, 4 glycosidic bonds (cellulose)

Question 5

branched monomer bonding pattern

Answer 5

a-1, 4 and a-1,6 glycosidic bonds (starch)

Question 6

proteins

Answer 6

• polymers of amino acids
• transport, regulation of DNA and RNA, enzymes, coordinate response to hormones, second source of energy

Question 7

amino acid monomers joined by?

Answer 7

peptide bonds to build proteins

Question 8

all amino acids have?

Answer 8

amino group, carboxyl group, R group

Question 9

3 groups of amino acids

Answer 9

electrically charged side chains, polar side chains, nonpolar side chains

Question 10

electrically charged side chains

Answer 10

can form ionic bonds or interact with water

Question 11

polar side chains

Answer 11

partial charges on side chains can form hydrogen bonds with water

Question 12

nonpolar side chains

Answer 12

no charged or polar groups to interact with water

Question 13

primary structure

Answer 13

• order of amino acids in a chain
• residue = amino acids - important for folding other structures
• amino acids can rotate around their peptide bonds
• flexibility important for folding other structures

Question 14

secondary structures

Answer 14

• first step of 3-D folding
• hydrogen bonds between carboxyl and amino groups
• a helix: right handed coil resulting from hydrogen bonding
• B pleated sheet: two or more polypeptide chains aligned after 1 big turn, hydrogen bonds form between the chains

Question 15

tertiary structure

Answer 15

• folding stabilized by disulfide bridges, van der waals forces, ionic bonds, hydrogen bonds between R side chains

Question 16

quaternary structure

Answer 16

• tertiary structures bond together, final functional form of protein
• results from the interaction of protein subunits by hydrophobic interactions, van der waals forces, ionic bonds, hydrogen bonds

Question 17

how can proteins be denatured?

Answer 17

heat, pH, salt, solvents; can refold if correct conditions are met again

Question 18

prions

Answer 18

misfolded proteins - can cuase disease

Question 19

nucleic acids

Answer 19

• polymers of nucleotides
• DNA stores information for making proteins
• important in monomer form (ATP, AMP, GTP)
• built 5’ -> 3’
• polar
  -joined by phosphodiester bonds

Question 20

what makes up nucleotides

Answer 20

phosphate, nitrogenous base, pentose sugar backbone

Question 21

cell functions of nucleotide monomers

Answer 21

ATP, GTP, cAMP

Question 21

phosphodiester bonds

Answer 21

strong covalent; hold together nucleotides

Question 22

nucleotide base pairs bonded by?

Answer 22

hydrogen bonds

Question 23

RNA

Answer 23

uses DNA to make proteins, enzymes, gene regulatory units, signaling, etc

Question 24

protein synthesis process

Answer 24

DNA - transcription - RNA - translation - protein

Question 25

active transport requires?

Answer 25

1) input of energy 2) carrier protein to move it across membrane (protein pump)

Question 26

lipids

Answer 26

- not polymers - long chains of hydrocarbons - hydrophobic - degree of saturation affects fluidity and permeability - mostly built by nonpolar covalent bonds between hydrogen and carbon

Question 27

amphipathic

Answer 27

hydrophobic and hydrophilic regions

Question 28

fatty acids

Answer 28

- amphipathic - lipid tails + carboxylic acid group

Question 29

saturated lipid

Answer 29

single bonds - usually solid at room temp

Question 30

unsaturated lipid

Answer 30

single and double bonds - can be arranged in trans or cis - usually liquid at room temp

Question 31

lipid bilayers

Answer 31

molecules that spontaneously arrange bc of how different regions of phospholipids interact with water

Question 32

phospholipid

Answer 32

fatty acid tail + phosphate head tail = hydrophobic / non polar head = hydrophilic / polar

Question 33

how are fatty acid tails stabilized?

Answer 33

van der waals interactions with each other

Question 34

phosphate heads stabilized by?

Answer 34

hydrogen bonds with water and each other

Question 35

homeoviscous adaptation

Answer 35

cells can adapt to changing temperatures by adjusting the composition of lipids to maintain optimal membrane fluidity

Question 36

what can stabilize the lipid bilayer at higher temperatures and more fluid at low temperatures?

Answer 36

cholesterol

Question 37

what can cross a lipid bilayer?

Answer 37

small nonpolar molecules (always), small uncharged polar molecules (not as quickly), large uncharged polar molecules (maybe once in a while), small ions (never)

Question 38

simple diffusion of hydrophobic molecules

Answer 38

- passive - requires concentration gradient - molecules move down concentration gradient - lipid bilayers permeable to hydrophobic molecules so they can diffuse freely in and out of cell

Question 39

plasma membranes

Answer 39

fluid mosaic structures, components move laterally and can change depending on needs of cell (non rigid), made of more than one type of biomolecule, surround organelles and entire cell

Question 40

peripheral membrane protein

Answer 40

outside of membrane - can be exterior or interior of cell

Question 41

integral membrane protein

Answer 41

embedded into membrane; change permeability of plasma membranes

Question 42

4 critical functions of plasma membranes

Answer 42

1) barrier 2) attachment to other things 3) recognizes signals and responds 4) allow some things to enter and some things to leave

Question 43

facilitated diffusion

Answer 43

movement of molecules from high to low concentration through protein tunnel - passive transport

Question 44

channel proteins

Answer 44

only allow specific molecules through, lets many specific molecules through when open

Question 45

carrier protein

Answer 45

- only allow specific molecules through - typically 1-3 for each change in shape - bonding to solute molecule changes shape of protein which allows solute to move across bilayer

Question 46

aquaporin

Answer 46

channel protein specific to water, can allow up to 100 million H2O molecules per second, facilitate osmosis by increasing permeability of membrane to water