bio exam 2 practice quiz questions

provide the complementary strand of DNA, given the template 5' - ATGACCTAGGAACAG - 3'

(start from the right side) 5' - CTGTTCCTAGGTCAT - 3'

The monomeric subunit of a nucleic acid is a nucleotide. a nucleotide consists of A ________________, B _______________, and C ______________. A key difference between DNA and RNA is that RNA has a hydroxyl (-OH) group rather than a hydrogen (-H) that occurs at ____________

- a nitrogenous base - a phosphate group - a pentose sugar -the 2' carbon

DNA polymerase synthesizes DNA in the _________ direction. the leading strand is synthesized continuously because DNA polymerase can move along the strand without interruptions; therefore ________ is the leading strand. The lagging strand is not synthesized continuously; __________ represents the lagging strand

-5' to 3' direction -strand B (3') -strand A (5')

The intermediate electron carrier nicotinamide adenosine dinucleotide (NAD+) plays an important role in glycolysis. consider the redox reaction of NAD+ as the reaction below H2 + (NAD+) = (NADH) + (H+) NAD+ is _____ to NADH as a result of the ____ of electrons

-reduced -gain

chloroplast structure

-the storm is where the light independent reactions of the Calvin cycle occur -the thylakoid is where the light dependent reactions occur

what components are needed for DNA replication to occur?

1. something to copy : template 2. Building blocks : nucleotide triphosphates 3. does the copying : DNA polymerase

order the flow of electrons in the light dependent reactions of photosynthesis

1. splitting of water 2. photons and photosystem II 3. Cytochrome b6-f complex 4. photons and photosystem II 5. NADP reductase

place the following list of events in order as they occur on the leading strand of DNA in replication

1. unzipping of DNA double helix 2. appearance of the replication fork (y-shaped) 3. binding of primer on which DNA polymerase can bind 4. winding of newly synthesized DNA into double helix

suppose that a DNA molecule is composed of 20% adenine. using chargaffs rules, what are the percentages of the other nitrogenous bases that compose this DNA molecule?

20% thymine 30% guanine 30% cytosine Total : 100%

DNA polymerase would add to the next upcoming nucleotide at the ___________ location of the nucleotide. in order for DNA polymerase to start replication, an ___________ is needed to initiate the process

3' sugar location -RNA primer

DNA polymerase synthesizes DNA in the __________ direction

5' to 3' direction

which of the following is true for the redox reaction below : A : +B ---> A+ + B-

A is oxidized, B is reduced

High-energy electrons that are carried from the previous stages of respiration (i.e., glycolysis, pyruvate oxidation, and the Krebs cycle) first enter the electron transport chain (ETC) in the protein complex A _______________ . They then travel to ubiquinone where electrons travel down their gradients by releasing energy, and then to B ___________ where more energy is released. Electrons then proceed to the carrier termed cytochrome c where electrons further release energy and travel down their gradients, and move to C _____________. This process only occurs when the terminal electron acceptor is D. ______________ . Notice the transport of protons (H+) through the protein complexes, powered by the release of energy from electrons as they are transported through the ETC; these protons are transported from the E _______________ to the F.________________ .

A. NADH dehydrogenase B. BC1 complex C . cytochrome oxidase complex D. oxygen E. mitochondrial matrix F. inter membrane space

select ALL of the following answer choices that are true according to Chargaffs rules about the proportion of nucleotides in a DNA molecule

A=T C=G -The amount of adenine equals the amount of thymine. -The amount of cytosine equals the amount of guanine. -The amount of purines equals the amount of pyrimidines

during carbon fixation, energy must be utilized for the reactions to occur. what is the source of this energy?

ATP hydrolysis and the oxidation of NADPH to NADP+ Since energy must be utilized to power the Calvin cycle, energy-releasing processes are used. ATP hydrolysis (ATP → ADP + Pi + energy) and oxidation of NADPH to NADP+ (losing electrons) release energy. The energy released from these processes is utilized in reactions of the Calvin cycle.

pyruvate oxidation produces _____ for the Krebs cycle

Acetyl-CoA

match the enzymes with their functions in DNA replication

DNA helicase : unwinds the DNA Single stranded binding proteins (SSBs) : hold the two strands of DNA apart Primase : Generates an RNa primer so that DNA polymerase can bind to the strand DNA ligase : seals the nicks in between Okazaki fragments

match the enzymes with their functions in DNA replication

DNA polymerase : synthesizes the new strands of DNA DNA gyrase : relieves torsional strain of the DNA double helix to prevent supercoiling Telomerase : synthesizes repeat sequences at the ends of linear chromosomes to protect from DNA damage (or to prevent shortening of chromosomes)

match the sources of energy that are harvested during each stage of respiration

Glycolysis : 2 ATP and 2 NADH Pyruvate oxidation : 2 NADH Krebs cycle : 2ATP + 6NADH + 2FADH2 Electron transport chain and Chemiosmosis : 28 ATP

DNA organization : prokaryotic replication

circular

termination : prokaryotic replication

circular chromosome - no enzyme needed to replicate the 'ends'

match the following events with either the light dependent reactions (light reactions) or the light independent reactions (Calvin cycle)

conversion of water molecules into oxygen : light dependent reactions formation of 3 carbon sugars : light independent reactions (Calvin cycle) sunlight is the source of energy : light dependent reactions carbon fixation, reduction, and regeneration of RuBP : light independent

glycolysis happens in

cytosol

anaerobic respiration

electron receptors are inorganic molecules

fermentation

electron receptors are organic molecules

aerobic respiration

electron receptors are oxygen molecules

endergonic reactions are

not spontaneous

classify the following organisms as heterotrophs or autotrophs

plants : autotrophs humans : heterotrophs Green algae : autotrophs Fungi : heterotrophs

enzymes involved in DNA replication

prokaryotes : DNA polymerase I, II, II eukaryotes : DNA polymerase

site of replication

prokaryotes : cytoplasm eukaryotes : nucleus

origins of replication of DNA

prokaryotes : one origin eukaryotes. : many on different chromosomes

overall process of DNA replication

prokaryotes : relatively simple eukaryotes : more complex

mode of replication of DNA

prokaryotes : semiconservative eukaryotes : semiconservative

glycolysis produces _____ for pyruvate oxidation

pyruvate

in photosynthesis, plants use chemical reactions to build glucose. the chemical equation for this process is 6CO2 + 6H2O = C6H12O6 + 6O2. in order to synthesize glucose, this reaction

requires energy and can be classified as an anabolic reaction

the results after the second round of replication of the Meselson-stahl experiment suggest that DNA is replicated by which model?

semiconservative

relative amount of time to complete a full replication : prokaryotic replication

shorter

exergonic reactions are

spontaneous

the sources of energy that are used to power the Calvin cycle come from

the light dependent reactions

Krebs cycle happens in

the matrix of mitochondria

electron transport chain

the protons that are transported by the protein complexes through the inner mitochondrial membrane move to the enzyme that is labelled as "A" in the figure. what is this enzyme called ? -ATP synthase

which of the following statements describes the enzyme telomerase

this enzyme is generally overactive in cancer cells

after DNA replication, the newly synthesized DNA double helix is an exact copy of its parental helix

true

autotrophs use photosynthesis to generate organic molecules and ATP as energy sources

true

the process of cellular respiration and photosynthesis represent an energy cycle. the products of one process serve as the reactants of the other proces

true

in the absence of carbohydrates such as glucose, other biological macromolecules such as lipids and proteins can be catabolized to obtain energy

true lipids can undergo β-oxidation to form acetyl-CoA, which enters the Krebs cycle. proteins can be deaminated into intermediates that feed into glycolysis and the Krebs cycle

Initiation : prokaryotic replication

has a single origin of replication

relative amount of time to complete a full replication : eukaryotic replication

longer

initiation : eukaryotic replication

many origins of replication

pyruvate oxidation happens in the

matrix of mitochondria

Hershey and chase demonstrated that _______ is the genetic material since ___________ was found in the bacterial pellet

-DNA -radioactive phosphorus

Select all statements that are true

-DNA polymerase 'reads' the strand in the 3' to 5' direction -DNA polymerase requires a primer to initiate replication -DNA synthesis occurs in the 5' to 3' direction for both the leading and lagging strands

The b6-f complex generates _____ by using the energy obtained from the electrons that pass through the complex. These protons are pumped into the _______. they move to the enzyme ______ where they travel down their concentration gradient, which _____________

-a proton gradient -thylakoid space -ATP synthase -generates ATP

which of the following is true about the process of cellular respiration?

-an input of energy is required for the process to begin -energy is harvested in the forms of ATP and electron carriers in glycolysis alone, 2ATP are required to 'prime' the reaction and 2 ATP molecules are harvested

The reactant that enters the Calvin cycle is ______. after the carbon fixation and reduction stages, the direct product of the cycle is _____________, which can be used to synthesize ____________

-carbon dioxide -glyceraldehyde-3-phosphate (G3P) -glucose

if an inhibitory molecule binds to an enzymes active site, it is termed to be an _____. meanwhile, if an inhibitory molecule binds to the enzyme at a location that is not the active site, it is termed to be ______

-competitive inhibitor -allosteric inhibitor

the chemical equation for cellular respiration is shown below C6H12O6 + 6O2 = 6CO2 + 6H2O Energy Is released as the bonds in _____ are systematically broken down. since energy is released, this reaction can be classified as _____. the energy obtained from respiration is harvested _____ for maximum efficiency

-glucose -exergonic -in small steps

in an endergonic reaction, the energy level of the reactants is ____ than the energy level of the products. this indicates that the reaction is _____. In an exergonic reaction, the energy level of the reactants is less than the energy level of the products. this indicates that the reaction is ______

-less -not spontaneous -greater -spontaneous

When we exercise for a period of time, our muscles begin to ache. This sensation is a result of the buildup of lactic acid as a result of lactic acid fermentation. Since fermentation is being used to synthesize energy, this means that _____________ are used as the terminal electron acceptors. This process is important because ________ can be regenerated. This molecule can be reduced to ________ in glycolysis, allowing the cell to obtain energy through this process.

-organic molecules -NAD+ -NADH

the Krebs cycle produces ____ for the electron transport chain

NADH and FADH2

which of the following are required for the complete oxidation of glucose? -glycolysis -krebs cycle -pyruvate oxidation -all of these reactions

all of these reactions these processes are connected - the products of one stage feed into the next stage as reactants

in noncyclic photosynthesis, the function of photosystem I is to oxidize water, releasing O2 as a byproduct

false

The complete aerobic respiration of glucose provides a net yield of 32 ATP for both prokaryotes and eukaryotes

false Think about where all the processes of respiration take place in the mitochondria. The 2 NADH molecules produced by glycolysis in the cytoplasm have to be actively transported into the mitochondria. Recall that active transport requires energy, approximately 1 ATP molecule to transport 1 NADH molecule.

only heterotrophs use the process of glycolysis to generate energy

false : ALL organisms can use glycolysis to generate energy

after a substrate binds to an enzymes active site and the reaction is catalyzed, the enzyme cannot be used again

false : enzymes are not used up during the course of a reaction

what type of bonds hold the complementary nitrogenous bases together ?

hydrogen bonds -there should be three bonds in the guanine-cytosine pair

DNA organization : eukaryotic replication

linear

termination : eukaryotic replication

linear chromosomes - telomerase is needed to replicate the ends

electron transport chain

what is the name of the process labeled as 'process 2' on the figure and what is its purpose? -chemiosmosis ; to use the energy from the diffusion of protons to phosphorylate ADP to generate ATP *chemiosmosis is where the most energy is generated.An electrochemical gradient is generated from the pumping of electrons to the intermembrane space by the electron transport chain. This allows for protons to diffuse down their concentration gradient through ATP synthase. This process provides the energy for ATP synthase to phosphorylate ADP.

electron transport chain

what is the name of the process that is labelled 'process 1' in the figure and what is its purpose ? -electron transport chain ; to produce a proton gradient

during DNA replication, the nucleotide uracil was mistakenly incorporated in to the growing DNA strand. can this mistake be repaired?

yes, DNA polymerase has 3' to 5' exonuclease activity, which can correct the mistake