Biology exam 2- dr. Kinkle

Fluid mosaic model

-hydrophilic heads of layer are outside and hydrophobic tails are inside

-integral proteins tether them together

-inside actin and intermediate filaments

-fluid is between proteins

membrane fluidity

as temp increases the membrane becomes more fluid

-bacteria have evolved to maintain a constant fluidity

-double bonds make them more fluid (unsat fat)

Integral vs peripheral membrane proteins

integral-all the way through

peripheral-one side of membrane

selective permeability

only allows some molecules through membrane/protein

diffusion vs osmosis

osmosis- water movement (high to low concentration) and free to move through aquaporins

diffusion-mc enter cell through channels to maintain conentrations

hypertonic vs hypotonic vs isotonic

hypertonic- water moves out of cell to cause shriveling

hypotonic- water moves into the cell to cause lysis (burst)

isotonic- solution is equal to the amount of water in the cell and out of cell

-in plant cells the same tings happen but the cell shrivels from the cell wall

active transport

-uses energy ATP/voltage

-use uniports- single type of mc

-symport- 2mc same direction

-antiport- 2mc different direction (Na/K)

Coupled transport

-uses engery stored from a gradient to move a mc against the concentration gradient

phagocytosis

particles engulfed

pinocytosis

liquids engulfed

receptor mediated endocytosis

bind to receptors/ specific types

what happens during a redox reation

-oxidation is the loss of an electron

-reduction is the gain of an electron

-more pot energy is reduced

2 laws of thermodynamics

1. energy cannot be created or destroyed only changed from one form to another

2. energy of the universe is increasing (G=H-TS

-to maintain order, life requires constant input of energy

Free energy equation

deltaG=deltaH-TdeltaS

endergonic vs exergonic reations

endergonic- more free energy than reactants (nonspontanious- entropy increases takes more energy to clean up (room)) +G

exergonic- reaction that produces less free energy than reactants (spontaneous entropy decrease) -G

ATP structure

Ribose, adenine, and three phosphate

Catalysts

-lower activation energy/free energy

-enzyme must fit active sites perfectly

-not used up

what are enzymes made of

-proteins with activation sites

-substrates bind to these and form enzyme-substrate complex

multienzyme complex

multiple enzymes catalyzing at different times in reation (metals)

cofactor

nonprotein components required by enzymes to function, for passing electrons

coenzyme

nonproteins organic mc, carrying electrons/energy

how temperature effects enzymes

higher temperature makes the enzyme denature

how does pH effect enzymes

optimum pH depends on where the enzyme is located- change in pH makes enzyme dissolve

competitive vs noncompetitive inhibitors

competitive- compete with substrate for same active site and prevents binding

noncompetitive- binding to site that is not the active sit but makes the enzyme change shape making the substrate unable to bind

autotrophs

making their own food through photosynthesis

heterotrophs

organisms that have to feed off of other plants or animals to get energy

the purpose of NAD/NADH

to reduce and oxidize other substances and carry electrons

substrate level phosphorylation

ATP is formed directly by added a phosphate group to ADP from PEP -part of glycolysis

Inputs of glycolysis

2 ATP, 2NAD+, glucose

Outputs of glycolysis

4 ATP, 2 NADH, 2 pyruvate

Net products of glycolysis

2 ATP, 2 NADH, 2 pyruvate

where is glycolysis occuring?

cytoplasm

Purpose of fermentation

when oxygen isn't available electrons are accepted to organic mc

what does fermentation make

lactic acid/ethanol

lactic acid fermentation

glycolysis forms 2 pyruvate, they are reduced by NADH to form NAD and lactate forms

alcohol fermentation

glycolysis form 2 pyruvate, CO2 is removed by forming acetaldehyde which is reduced by NADH forming NAD and ethonal

pyruvate oxidation

pyruvate is formed after glycolysis and CO2 is released, NAD is reduced to NADH and CoA is the result (2 carbon)

Krebs cycle

CoA is added to 4 carbon mc to make 6 carbon mc (citric acid)

-goal is to convert citric acid back to 4 carbon mc

inputs of krebs cycle (per glycose)

acetyl CoA, 6 NAD, 2 FAD and 2 ADP

outputs of krebs cycle (per glucose)

4 CO2, 6 NADH, 2 FADH2, 2 ATP

Electron transport chain

- H+ gradient forming by pumping H+ into inter membrane space

-gradient used to form ATP

Inputs of electron transport

NADH, FADH2

Outputs of electron transport

water, 26-20 ATP, NAD+, FAD

terminal electron acceptor of electron transport

O2

What part of cellular respiration causes feedback inhibition

phosphofructokinase

-ATP is an allostieric inhibitor of phosphofructokinase

where is the control point for oxidative phosphorylation

occurs at the enzyme pyruvate dehydrogenase- inhibited by NADH

where is the control point for the krebs cycle

enzyme citrate synthetase- inhibited by high levels of ATP

absorption vs action spectrum

objects absorb light that arent their actual colors

cyclic vs noncyclic photophosphorylation

cyclic reaction creates more ATP

light reactions

-generate ATP through H+ gradients, genrate NADPH which will be used to drive calvin cycle

anabolic reactions use

NADPH

catabolic reations use

NADH

carbon fixation

CO2 enters calvin cycle and combines with RuBP to form 3PG with Rubiso

- ATP and NADPH from light reaction are used to generate G3P which can be used to make glucose- ATP regenerate RuBP so the cycle can restart