Biology Exam #3

UNH Biology 411 with Paul Tsang

Celllular respiration is

anaerobic and aerobic

catabolic pathways yield energy by

oxidizing fuels (glucose)

the breakdown of organic molecules is

exergonic

fermentation is

partial degradation of sugars, without O2

aerobic respiration

consumes organic molecules and O2 and yields A T P

anaerobic respiration

consumes compounds other than O2

photosynthesis is

generates O2 and organic molecules, which are used as fuel for cellular respiration

during cellular respiration

fuel (glucose( is oxidized, and O2 is reduced

NAD+

functions as an oxidizing agent during cellular respiration

NADH (the reduced form of NAD+)

represents stored energy that is tapped to synthesize ATP

dehydrogenase enzymes

facilitate the transfer of two electrons and one hydrogen to NAD+, forming NADH

Glycolysis

breaks down glucose into two molecules of pyruvate in the cytosol

Pyruvate oxidation and the citric acid cycle completes the breakdown of glucose in the

mitochondrial matrix

Oxidative phosphorylation accounts for most of the A T P synthesis and occurs in the

inner membrane of the mitochondria

What occurs whether or not glucose is present

Glycolysis

A small amount of ATP is formed in glycolysis and the citric acid cycle by

substrate-level phosphorylation

______ __________ accounts for almost 90% of the A T P generated by cellular respiration

Oxidative phosphorylation

what are the inputs of glycolysis

2 ATP + glucose

what are the outputs of glycolysis

2 pyruvate + 2 ATP + 2 NADH

what are the inputs of pyruvate oxidation

2 pyruvate

what are the outputs of pyruvate oxidation

2 Acetyl-CoA + 2 CO2 + 2 NADH

what are the inputs of citric acid cycle

2 Acetyl-CoA, oxaloacetate

what are the outputs of the citric acid cycle

2 ATP + 6 NADH + 2 FADH2 + 4 CO2

Which respiration produces less ATP

aerobic- uses more to create ATP

_________ is the flow of hydrogen ions down a gradient through ATP synthase

chemiosmosis

the stroma is ____ concentration H+

low

the thylakoid space is _____ concentration H+

high

the mitochondrial matrix is ______ concentration H+

lower

the inner membrane space is _____ concentration H+

higher

the first protein complex oxidizes ______ to become ______

NADH: NAD+

the second protein complex oxidizes ______ to become _____

FADH2: FAD

the fourth protein complex reduces _____ to become______

hydrogen and oxygen: water

ATP synthase occurs in ______ phase

chemiosmosis

the gradient formed by ETC is used by _______ to create more ATP

ATP synthase

in fermentation pyruvate is converted into _______

ethanol

the cell performs fermentation when

there is no final electron acceptor (oxygen) to do cellular respiration

Fermentation only includes the phase _______

glycolysis- all other phases come to a halt because they require oxygen

fermentation glycolysis is supposed to

oxidize NADH so that NAD+ can catch electrons and make ATP

fermentation types

lactic acid, alcohol (ethanol)

lactic acid fermentation is

pyruvate gets reduced into lactic acid using NADH- NADH oxidized to NAD+

alcohol fermentation is

the conversion of pyruvate into acetaldehyde- releasing CO2, acetaldehyde gets reduced into ethanol using NADH- NADH oxidized to NAD+

Oxidation is ______

loss of electrons

Reduction is ______

gain of electrons

Bread expands because ______ uses alcohol fermentation which produces CO2, causing ______

yeast: bubbles

during alcohol fermentation, pyruvate produced in glycolysis is converted into _______ and reduced into _______ using NADH

acetaldehyde: ethanol

____ are produced during fermentation

2

glycolysis accepts a wide range of ___________

carbohydrates

_______ must be digested into ______ ______ and can be plugged into glycolysis, pyruvate oxidation or Krebs cycle

proteins: amino acids

fats can be digested into _______ to be used in ________ or ______ ______ to be used in _____ _____

glycerol, glycolysis: fatty acids, Krebs cycle

fatty acids are broken into two fragments by _____ ________, this yields ____-____

beta oxidation: Acetyl-Coa

an oxidized gram of _____ produces more than twice as much ATP as a ____ of ____________

fat: carbohydrate

triglyceride is the most common type of fat in the human body, lipase can break it down into _____ _____ or ______

fatty acid: glycerol

beta-oxidation is a form of ___________- it breaks down large molecules to power the processes

catabolism

taking oxaloacetate and forming an amino acid is a form of _________ - it builds molecules to

anabolism

what reaction takes place in the stroma

Calvin cycle reaction

what reaction is carried out by the thylakoid membrane

light reaction

________ reactions convert light energy into ATP and NADPH

light

________ reactions use ATP and NADPH to convert CO2 into sugar

Calvin cycle

_______ reactions split water molecules and release oxygen

light

________ reactions return ADP, Pi and NADP+ to light reaction

Calvin cycle

photosynthesis occurs in _________

chloroplasts

cellular respiration occurs in ________

mitochondria

what is the initial source of electrons for the chloroplast electron transport chain?

Water

Which of the following components is not used by both plants and cyanobacteria to carry out photosynthesis?

chloroplasts

Which statement about thylakoids in eukaryotes is not correct?

Thylakoids exist as a maze of folded membranes.

From which component of the light-dependent reactions does NADPH form most directly?

photosystem I

Where in eukaryotic cells does the Calvin cycle take place

chloroplast stroma

Central Dogma

DNA → Transcription → mRNA → Translation → Protein

three phases of the Calvin cycle

fixation, reduction, regeneration

phase I: carbon fixation

addition of CO2 molecule to be catalyzed

phase II: reduction

reduction of ATP into ADP and oxidation of NADPH into NADP+

phase III: regeneration

carbon compounds from reduction are

does photosystem I or II come first

photosystem II

in hot dry weather plants _____ their stomata to ______ water

close: save

in photorespiration rubisco fixes _______ instead of _______, consuming more ATP than it makes

oxygen: carbon dioxide