Biochemistry Exam 3

lipid

water insoluble molecule that’s highly soluble in organic solvents

no

do lipids form polymers

storage and membrane

2 types of lipids

free fatty acids, triacylglycerols, phospholipids

3 types of storage lipids

glycolipids, steroids

2 membrane lipids

free fatty acids

non-esterified fatty acids

triacylglycerols

storage form of fatty acids

phospholipids

bears a charged phosphoryl group, creating a macromolecule with a polar head and nonpolar tail

glycolipids

bound to carbohydrates and are important membrane constituents

steroids

polycyclic hydrocarbon lipids

saturated

fatty acid with no double bonds

unsaturated

fatty acid with at least one double bond

carbon chain and carboxyl group

what makes up a hydrocarbon

unsaturated

_______ fatty acids have lower melting points

shorter

______ chain, lower melting point

cis

cis or trans fatty acids increases fluidity

short

do short or long C chains enhance fluidity

down, down, up

for more fluidity, (down,up) mp, (down,up) C’s,(down,up) dbs

decrease

does high concentration of free fatty acids increase or decrease the pH

fatty acids

do fatty acids or carbs have more energy

do glycogen or triacylglycerols store more energy

adipose tissue

where is a lot of our triacylglycerol

fatty acid, platform, phosphate, alcohol

4 components of phospholipid molecule

2, glycerol

phosphoglycerides have _ fatty acid chains and a _____ backbone

glycolipids

sugar containing lipids

outside

is the sugar unit of glycolipids always on the inside or outside of the membrane

lipids proteins carbs

3 components of membranes

no

are membranes symmetric

inside

is the inside or outside of the membrane typically negative

hydrophobic effect

major driving force for formation of lipid bilayers

van der waals

what forces act between hydrocarbon tails in lipid bilayer

long

do long or short fatty acids favor the rigid structure

lowers

cis double bond ____ Tm

high

____ cholesterol lowers Tm

increases

high cholesterol _____ membrane fluidity

ions and (most) polar molecules

what are lipid bilayers highly impermeable to

water

polar molecule exception that goes through the membrane easily

ions

are ions or polar molecules more impermeable

lateral

rapid diffusion method

tranverse

slow diffusion method

tranverse diffusion

flip flopping diffusion

lateral diffusion

a lipid moving to one side or another in the membrane

simple diffusion

some molecules pass through the membrane this way, they dissolve in the lipid bilayer, lipophilic molecules

facilitated diffusion

sodium ions pass through a channel in this kind of diffusion

passive

gradient driven transport

active

energy driven transport

3 2

_ Na out, _ K in

H and K

what ions are involved in the gastric pump that lowers the pH in the stomach

Ca

ion transferred out of the cytoplasm and into extracellular fluid, mitochondria, and sarcoplasmic reticulum of muscle cells for muscle contraction

secondary transporters

thermodynamically uphill flow of one species of ion or molecule is coupled to the downhill flow of a different species

secondary active transport

example: sodium gradient is generated by Na K ATPase pump, can power active transport of other molecules when the sodium flows back down its gradient passively

sodium glucose linked transporter

symporter powered by the simultaneous entry of Na

antiporter

secondary transporter protein, couple downhill with uphill

symporter

secondary transporter protein, couple uphill with uphill

spontaneous

if resolvation E is greater than desolvation E, interaction with channel is _______

5

how many steps in general signal transduction pathway

thymine

what base does uracil replace in RNA

cytosine thymine uracil

pyrimidine bases

adenine and guanine

purine bases

pyrimidines

do purines or pyrimidines have one ring

2 prime C (from the right)

where is the extra OH in ribose sugar

nucleoside

a unit consisting of a base bonded to a sugar

thymine

only nucleoside in DNA without “deoxy” in the beginning of the name

5-3

DNA and RNA are made up of _-_ phosphodiester linkage

hydrogen bonds

what holds the base pairs together

semiconservative

DNA replication is _______

half the helical structure is lost (DNA)

Tm is the temperature at which

annealing

name of the REnaturation process

more

G-C bonds have more or less H bonds than A-T

G C

what base pair makes DNA more stable

B

most common DNA form

major

which DNA groove shows more features

histones

small basic proteins eukaryotic DNA is attached to

arginine and lysine

what amino acids are commonly in histones

negative, positive

DNA is ____ protein is ______

nucleosome

core particle in eukaryotic DNA

helicase

enzyme that unwinds and unzips the DNA, breaking H bonds

replication fork

what does the helicase create in the DNA

primer

addition of what starts DNA synthesis

RNA

what are the primers made of

primase

what adds primer to DNA for synthesis

DNA polymerase

enzyme that binds to the primer and adds complementary DNA bases

okazaki

fragments synthesized with the lagging strand

exonuclease

what enzyme removes all the RNA primers from the strands

DNA polymerase

what fills the gaps from the primers being removed

DNA ligase

what enzyme joins the Okazaki fragments together

mRNA

RNA that’s readable and used to produce proteins

gene

simple stretch of DNA that contains instructions for making a protein

RNA polymerase

what separates the DNA strands in transcription

ribosome

where does the mRNA go to be translated

RNA

single stranded nucleic acid

sugar phosphate and nitrogenous base

3 things in DNA

cytoplasm

where is RNA found that DNA isn’t

mRNA

carries genetic information from DNA to ribosomes for protein synthesis

tRNA

brings amino acids to the ribosome during translation

rRNA

forms the core of ribosomes and catalyzes protein synthesis

initiation elongation termination

3 stages of translation

Met-tRNA synthetase

what catalyzes attachment of Met to tRNA to help initiate translation

small

does tRNA bind to the small or large subunit

A site

site where tRNA initially binds