Learn: doom and despair (bio151 exam 1)

cell theory

all organisms are composed of cells, microorganisms today come from pre-existing microorganisms

DNA --> RNA --> protein

information flow

DNA is transcribed into RNA, RNA is translated to protein

phospholipid

amphipathic, polar head group in hydrophilic & hydrophobic hydrocarbon chain tail

Wohler

urea - living organisms are governed by the same chemicals as non-living systems

carbohydrates

structural support, energy source

proteins

structural support, energy source

nucleic acids

genetic information, some RNA acts as ribosomes

lipids

cell membranes, store energy

hydrolysis

adds a water molecule

structural polysaccharides

cellulose (glucose polymer), chitin, amino acids, ones made from monosaccharides

monosaccharides

simple sugars, 6Cs, linear or ring

glycosidic linkages

carbohydrate bonds

storage polysaccharides

starch and glycogen, can be broken down when energy is needed

amino acids

amino group, a carbon, carboxyl group, R group

tetrahedral

R group determines hydrophobic or hydrophilic

peptide bonds

amino acid linkages

polypeptides

N & C terminus, repeating but variable structure

primary structure

sequence of amino acids

3 or 1 letter abbreviations (amino --> carboxyl)

R groups on opposite sides

affects protein folding

secondary structure

interactions from nearby amino acids

a-helix and b-sheet

tertiary structure

3D shape of polypeptide

covalent bonds important for stabilizing proteins that function OUTSIDE of the cell

quaternary structure

interactions between polypeptide subunits

changes in primary structure can lead to changes in this

ATP synthase

alpha helix

secondary structure, very stable, hydrogen bonds between amino and carboxyl groups

beta sheet

secondary structure, can be pleated or parallel/antiparallel

stabilized by lateral H bonds

denaturation

can be reversible (tertiary only) or irreversible

thymine

only in DNA

anfinsen experiment

RNAse can refold

translation

proteins spontaneously fold

begins in cytosol

x-ray crystallography

used to determine protein structure

cryoelectron microscopy

doesn't require protein crystallization, used to determine protein structure

protein chaperones

can help refold misfolded proteins

typically coupled to ATP hydrolysis

prions

misfolded proteins that can "corrupt" correctly folded versions of the same protein

nucleotides

5C sugar (ribose), nitrogenous base, 5'phosphate, 3'-OH

deoxynucleotides

DNA building blocks

nucleoside

nucleotide with NO phosphate

pyrimidines

single ring, CU

(CUt the PYe)

purines

double ring

(PURe AGony)

phosphodiester bond

links two nucelotides

bond formed at 5' phosphate and 3' OH groups

Watson and Crick

discovered DNA structure, used x-ray crystallography

sugar-phosphate backbone

double helix has a major and minor groove

C-G (3), A-T (2)

the nitrogenous pairs of DNA inside the helix (2 and 3 hydrogen bonds)

stabilize DNA

hydrogen bonding and base stacking do what...

tRNA

important for protein translation

fatty acids

hydrocarbon tails, saturated or unsaturated

saturated

no C double bonds, tight packing

unsaturated

C double bonds, kinky

triacylglycerols

3C glycerols and fatty acids, hydrophobic

LDFs

fatty acid tail interactions are allowed by...

trans fatty acids

or trans or cis fatty acids more unsaturated?

LDLs

contain triacylglycerols surrounded by phospholipids with cholesterol and other proteins, bad cholesterol

membrane functions

permeability barrier

separation of organelles

transport of material in/out of cells/organelles

detect signals

cell-cell & cell-matrix interactions

phospholipids

key part of membranes

bilayers

spontaneously formed by phospholipids

lipids in membranes

dynamic, can rotate and laterally diffuse

movement to other half of membrane is slow, can be aided by catalysts

cholesterol

buffer in membranes, amphipathic

proteins in the membrane

have different functions, transporters, receptors, enzymes, adhesion

integral membrane proteins

permanently associated with the membrane, can cross the entire membrane

peripheral membrane proteins

temporarily associated with either side of the membrane

fluid mosaic model

bleaching and following a protein, shows proteins are mobile, supports the...

simple diffusion

passive movement across a semi-permeable membrane, high to low conc.

facilitated diffusion

movement through transporters embedded in the membrane, high to low conc

- can involve cotransport (coupled transport)

osmosis

water movement across a semi permeable membrane, water will move from low solute conc. to high solute conc., will eventually reach equilibrium

contractile vacuoles

absorbs excess water in the cell and expels it

red blood cells

can shrink or expand based on solute conc.

hypertonic

HIGH solute conc.

hypotonic

LOW solute conc.

turgor pressure

occurs when water moves into the cell through osmosis

uniport

transporter allows movement of ONE coupled solute

aquaporins

facilitated water transporters, 4 hydrophobic subunits

can facilitate water movement when added to cells that don't normally make them

symport

2 solutes moving in the SAME direction

antiport

2 solutes moving in OPPOSITE direction

primary active transport

moves solutes against their concentration gradient, uses ATP,

secondary active transport

moves one solute via active transport and a second "comes along for the ride", against conc. gradient

glucose

can treat a life-threatening sodium (NA+) drop, enables uptake through the Na/glucose transporter in the intestine

cystic fibrosis

mutation in an active transporter, osmosis fails

prokaryotic cells

no nucleus, little/no internal compartmentalization

eukaryotic cells

nucleus, bigger, membrane-bound organelels

endomembrane system

compartmentalizes/localizes cellular functions, allows trafficking of cellular components surrounded by membranes (vesicles)

exocytosis

fusion of vesicle with the cell's plasma membrane

release components OUT of cell

endocytosis

internalizes materials from the surface to make new vesicles

bring components INTO the cell

nuclear envelope

double membrane surrounding nucleus

regulates traffic in/out of nucleus

continuous with endoplasmic reticulum

nuclear pores

regulate in/out movement of solutes and macromolecules

small molecules - diffusion

RNA, larger molecules - transporters

endoplasmic reticulum

site of protein and lipid synthesis

rough ER and smooth ER

rough ER

studded w/ ribososmes, synthesizes proteins that will be secreted and transmembrane proteins

smooth ER

site of lipid synthesis

golgi appartus

helps with protein and lipid synthesis and storage

flattened sacs - cisternae

enzymes chemically modify proteins and lipids in different places

lysosomes

specialized vesicles derived from the golgi

degrade damaged/unneeded molecules

pH 4-5 (maintained by proton pump)

receptor-mediated endocytosis

vesicle formation triggered by solute binding to receptors

plasma membrane

emptied receptors are recycled to the _______ by the same vesicle

mitochondria and chloroplasts

have double outer membranes, divide independently of the cells in which they're found, and contain their own circular genomes (DNA)

endosymbiosis

- resemble bacterial ribosomes

- have own genomes (circular DNA) resembling bacterial genomes

- multiply independently of cell using proteins via binary fission

mRNA

are bound in the cytosol by ribosomes

rough ER

proteins destined for the endomembrane system are produced at the...

(squirted into lumen)

inserted into a membrane

proteins that remained inserted into a piece of the ER membrane will be...

proteins destined for secretion or plasma membrane

have ER-targeting signal sequences

signal sequence is bound by the signal recognition particle (SRP)

SRP binds, translation pauses until SRP binds to SRP receptor on the ER

proteins destined for cell surface

- maintain their orientation in the membrane

- membrane proteins produced by ribosomes on the RER

- extracellular part sticks into lumen

- cytoplasmic part remains in cytoplasm

extremophiles

more drastic membrane temperature adaptations

cytoskeleton polymers

microfilaments, intermediate filament, microtubule

cytoskeleton

provides internal structural support

enables transport within the cell via motor proteins

made of long protein subunits

form elaborate networks in cells

microtubules

dynamic, grows quickly at + end, - end embedded in central organizing center (centrosome)

important for chromosome segregation in cell division

allow vesicle transport & beating of cilia and flagella

grow quickly at advancing end of crawling cells

motor proteins in cilia and flagella

how do microtubules slide?

dyneins

motor proteins in MTs

moves cargo towards - end of MTs

use ATP

motor proteins

move vesicles along MT tracks