Biology Quiz 5

In Electron Transport Chain and Phosphorylation, what is the first step?

Complex 1 picks up high energy electrons from NADH and conducts them via two electron carriers, FMN(Flavin mononucleotide) and an Fe/S(iron sulfure) protein, to ubiquinone

In Electron Transport Chain and Phosphorylation, what is the second step?

Complex 2 oxidizes FADH2 to FAD; the two electrons released are transferred to ubiquinone and the two protons released go the matrix. electrons that pass to ubiquinone by the complex 2 reaction bypass complex 1 of the elctron transfer system.

In Electron Transport Chain and Phosphorylation, what is the 3rd step?

complex III accepts electrons from ubiquinone and transfers them through the electron carriers in the complex-cytochrome b, an Fe/S protein, and cytochrome c1 to cytochrome c, which is free in the intermembrane system

In Electron Transport Chain and Phosphorylation, what is the 4th step?

complex IV accepts electrons from cytochrome c and delivers the, via electron carriers cytochromes a and a3 to oxygen. Four protons are added to a molecule of O2, as it accepts 4 electrons forming 2H2O

In Electron Transport Chain and Phosphorylation, what is the 5th step?

As electrons move through the electron transfer system, they release free energy. Part of the released energy is lost as heat, but some is used by the mitochondrion to transport H+ across the inner mitochondrial membrane from the matrix to the intermembrane compartment at complexes 1,3,4

In Electron Transport Chain and Phosphorylation, what is the 6th step?

the resulting H+ gradient supplies the energy that drives ATP synthesis by ATP synthase

In Electron Transport Chain and Phosphorylation, what is the 7th step?

because of the gradient, H_ flows across the inner membrane and into the matrix through a channel in the ATP synthase

In Electron Transport Chain and Phosphorylation, what is the 8th step?

the flow of H+ activates ATP synthase, making the headpiece and stalk rotate

In Electron Transport Chain and Phosphorylation, what is the 9th step?

as a result of changes in shape and position as it turns, the headpiece catalyzes the synthesis of ATP and ADP and Pi

What is the flow of electrons through a series of proton pumps, and the energy released builds n H gradient across the inner mitochondrial membrane

electron transfer system

What is it called when ATP synthase catalyzes ATP synthesis using energy from the H+ gradient across the membrane?

chemiosmosis

ETC is a series of (1) embedded in the (2)

1.membrane bound electron carriers 2.inner mitochondrial membrane

Where does the ETC get its electrons from?

NADH and FADH2

Which three major protein complexes in the inner mitochondrial membrane serve as electron carriers?

I, III, IV

Which complex is bound to the inner mitochondrial membrane on the matrix side?

II

Electrons from NADH enter the ETS at complex (a) - electrons from FADH enter the ETS at complex (b)

a.I b.II

In the ETS, what does the free energy from electron release used for?

build the H gradient across the inner mitochondrial membrane

There is a [a] H concentration in the intermembrane compartment and a [b] H concentration gradient in the matrix

a. high b.low

The H gradient supplies energy that drives ATP synthesis by …

mitochondrial ATP synthase

which electron transport carriers shuttle electrons between major complexes?

cytochrome c and ubiquinone(coenzyme Q)

What are the proteins with a heme prosthetic group that contains an iron atom that accepts and donates electrons?

cytochromes

Which complexes actively transport protons from the matrix to intermembrane compartment

I, III, IV

What is the energy from the electrochem gradient caused by the proton concentration used for?

ATP synthesis and cotransport of substances to and from mitochondria

What enzyme is embedded in the inner mitochondrial membrane and synthesizes ATP?

ATP synthase

What does ATP synthase use to add phosphate to ADP and generate ATP

proton motive force

How does the accumulation of protons in the intermembrane space drive into the matrix

diffusion

Where is ATP synthase located in reference to the mitochondria?

between the matrix and the intermembrane space

on ATP synthase, how does the basal unit in the inner membrane connect to the headpiece located in the matrix?

a stalk

What bridges the basal unit and headpiece on atp synthase?

a peripheral stator protein

How does H flow power atp synthesis in synthase

it rotates the headpiece

What is the theoretical yield of ATP in eukaryotes?

36

What is the theoretical yield of ATP inbacteria

38

The true energy yield in eukaryotes is (a) ATP while prokaryotes is (b)

a.30 b.32

What is the reduced energy yield in aerobic respirtaion due to?

energy leakage in the inner membrane and the use of proton gradient for purposes other than ATP synthesis

What did E racker of Cornell and W Stoechenius of UCSF show in their experiment?

The H gradient powers ATP synthesis by ATP synthase

What was the process of the experiment done by E racker and W stoekenius

They made membrane vesicles that had a proton pump and ATP synthase to determine whether proton motive force drives ATP synthesis

When oxygen is present, what is pyruvate oxidized to?

acetyl CoA which enters the krebs cycle

Without oxygen, what is pyruvate forced to do

it is reduced to oxidize NADH back to NAD+ in fermentation

What are the two types of fermentation

lactate and alcoholic

In lactate fermentation, what is converted to form lactate

pyruvate

In alcoholic fermentation, what is pyruvate converted to

ethyl alcohol and CO2

Which of the following is able to switch between fermentation and full oxidative pathways depending on the oxygen supply, an example being muscle cells

facultative anaerobes

In strict anaerobes, why is fermentation the only source of ATP for some bacteria and fungi?

they lack the enzymes to carry out oxidative phosphorylation

What is it called when higher than normal rates of glycolysis occurs in usually cancer cells

Abnornal glycolysis

Abnormal glycolysis generates a large amount of __

lactate

In the catabolism of proteins, proteins are broken down into amino acids and then their amino acids undergo what to remove the amino group?

deamination

In the catabolism of proteins, Alanine is converted to (1), aspartate is converted to (2), glutamate is converted to (3)

1.pyruvate 2.oxaloacetate 3.alpha-ketoglutarate

What is it called when glucose is made from the intermediates created by glycolysis and citric acid cycle that supplies molecules from which many other cellular molecules are synthesized

gluconeogenesis

What is broken down to make fatty acids and glycerol?

fats

In the catabolism of fat, fatty acids are converted to

acetyl groups by Beta oxidation

How much more energy does 6 carbon fatty acids provide than 6 carbon glucose

20%

How do prokaryotic cells divide?

binary fission

For which cells is the DNA a single circular double stranded molecule

prokaryotes

Where does DNA replication start in prokaryotes?

Ori C

Where do all eukaryotic cells store genetic information?

chromosomes

How many chromosomes do human cells have

46

What are the stages of the cell cycle

G1, synthesis, G2, Mitosis, Cytokinesis

Which of the following divides the replicated DNA equally and generates daughter cells that are exact copies of the parent cell

Mitosis

Which of the following produces daughter nuclei with half the number of chromosomes of the parental nucleus and are not identical to the parent

Meiosis

What separates the replicated DNA molecules precisely into the daughter cells

Mitotic Cytoskeleton

How many DNA molecules forms a chromosome?

1

Which type of proteins are responsible for packing the DNA into a shorter length so it can fit into the nucleus

histone proteins

What is the complex of DNA and all its associated proteins?

chromatin

What is formed when the DNA winds around the histones

Nucleosome

Which histones does DNA wind around?

H2A, H2B, H3, H4

What is the short segment of DNA that connects nucleosomes?

Linkers

What is responsible for compacting DNA by a factor of 7

10nm chromatin fibers

When further packing occurs by the 30nm chromatin fiber, the nucleosome and linker are bound by which histone protein

5th Histone protein H1

On the solenoid model, how nucleosomes are found on every turn

6

euchromatic is packed (1) and heterochromatine is packed (2)

1.loosely 2.densely

Between euchromatin and heterochromatin, which is expressed more strongly?

euchromatin

Where are replicated chromosomes (sister chromatids) connected?

centromere

What are the 2 copies of the chromosome within the replicated chromosome?

sister chromatids

How are sister chromatids held together?

cohesions

What is the equal distribution of chromosomes into each of the two daughter nuclei?

chromosome segregation

What is the number of chromosome sets in a cell or species?

ploidy

Cells that only have one copy of each type of chromosome in their nuclei are (1) while cells with two copies are (2), and cells with many are (3)

1.haploid 2.diploid 3.polyploid

what are the chromosomes from a pair in a diploid cell called

homologous chromosomes

what is an individuals particular array of chormosomes

karyotype

What phase can be entered during the G1 phase and makes the cell not proceed into replication, and sometimes the cell is able to go from it back into G1

G0

What cells are known for entering G0 and never going into G1

Neurons

How many hours does it take for eukaryotes to divide

24 hours

Which phase of the cell cycle is characterized by DNA replication

Synthesis

Which phase is the first period of growth and where the cell replicates proteins

G1

What is the second growth phase of the cell cycle

G2

How long is G1

10 hours

How long is Synthesis?

9 hours

How long is G2

4 hours

How long is mitosis?

1 hour

What are the 5 phases of mitosis in order

1.Prophase 2.Prometaphase 3.Metaphase 4.Anaphase 5.Telophase

What is the new apparatus formed to aid mitosis

spindle

What is the main microtubule organizing center of animal cells and many protists

centrosome

What is at the center of the centrosome that isn’t involved in spindle formation but are duplicated and divided

centrioles

What are the starlike arrays caused by mitrotubules extending from the centrosome

asters

What phase is when individual condensed chromosomes first become visible with the light microscope

prophase

which phase is when the spindles assemble and the nuclear envelope begins to disintegrate

prophase

Which phase is when the kinetochore forms on each sister chromatid and the microtubules bind to the kinetochores, and chromosomes begin to move to the center of the cell

prometaphase

What is it called when chromosomes move to the center of the cell

congression

Which phase is when the microtubules move the chromosome into the middle

metaphase

Which phase is the cell arrested into to form karyotypes

metaphase