3301 Final

the most basic function of the cell cycle is to duplicate accurately the vast amount of...

DNA in the chromosomes

DNA duplication occurs during which phase

S phase

how long does S phase take

8-12 hours

After S phase chromosome segregation and cell division occur in what phase

M phase

M phase involves a series of dramatic events that begin with

mitosis

where does DNA polymerase begin

origin of replication

how many strands open forming the replication forks

2

where do new strands for dna ploymerase grow

the forks

what is a helicase

enzyme which catalyze the unwinding and separation (breaking H-
Bonds) of the parental double helix.

what are single strand binding proteins

proteins which attach and help keep the separated
strands apart

what is topoisomerase

enzyme which relieves stress on the DNA molecule by allowing
free rotation around a single strand

what do rna primers do

start the addition of new nucleotides

what is primase

enzyme that polymerizes the rna primer

DNA polymerase catalyzes the...

stepwise addition of a deoxyribonucleotide to the 3'-OH end of a polynucleotide chain

The growing primer strand that is paired to...

an existing template strand

The newly synthesized DNA strand therefore polymerizes in which direction

5' to 3'

DNA polymerase is driven by a large favorable free energy change caused by the release of

pyrophosphate and its subsequent hydrolysis to two molecules of inorganic phosphate

the DNA synthesized on the lagging strand must be made initially as a series of short DNA molecules, called

okazaki fragments

On the lagging strand, the Okazaki fragments
are synthesized sequentially, with those nearest the fork

being the most recently made

in eukaryotes rna primers are made at intervals spaced by about how many nucleotides

200

each rna primer is approximately how many nucleotides long

10

this primer is erased by a special dna repair enzyme...which recognizes and rna strand in an rna/dna helix and fragments it

RNAse H

what does unwinding do

forms replication fork

what does primase do

synthesizes rna primer

continuous synthesis is what strand

leading

discontinuous synthesis is what strand

lagging

do silent mutations have phenotypic effect

no

do missense mutations have phenotypic effects

yes or no

do nonsense mutations have phenotypic effects

yes

The oxidation of long-chain fatty acids to... is a central energy-yielding pathway in
many organisms and tissues

acetyl-coa

in mammalian...it provides as much as 80% of the energetic
needs under all physiological circumstances

heart and liver

The acetyl-CoA produced from the fatty acids... completely oxidized to CO2 in the citric
acid cycle, resulting in further energy conservation

may be

In some species and in some tissues, such as in liver... may be converted to...water-soluble fuels exported to the brain and other tissues when glucose is
not available

acetyl-coa ketone bodies

The repetitive four-step process, called... by which fatty acids are converted into acetyl-coa

what is the first step for the complete oxidation of fatty acids to CO2 and H20

Oxidation of long-chain fatty acids to two-carbon fragments, in the form of acetyl-CoA ( b-oxidation)

what is b-oxidation

fully saturated fatty acids with an even number of carbon atoms is degraded to acetyl-coa

The enzymes of fatty acid oxidation in animal cells are located in the...

mitochondrial matrix

The fatty acids with chain lengths of... carbons enter the mitochondria without the help of membrane transporters

12 or fewer

Those with 14 or more carbons, which constitute the majority of the FFA obtained in the diet or released
from adipose tissue, cannot pass directly through the mitochondrial membranes—they must first undergo

the three enzymatic reactions of the carnitine shuttle

the first of three enzymatic reactions of the carnitine shuttle is catalyzed by what

acyl-CoA synthetases

Fatty acyl–CoA esters formed at the cytosolic side of the...can be transported
into the mitochondria and oxidized to produce ATP, or they can be used in the cytosol to synthesize

outer mitochondrial membrane

Fatty acyl–CoAs, like acetyl-CoA, are high-energy compounds; their hydrolysis to FFA and CoA has a large, what free energy change

negative standard free energy change

Conversion to the carnitine ester commits the fatty acyl moiety to the...

oxidative fate and it is a regulation point

fatty acyl-Coa will go to two organelles what are they

mitochondria for ATP and cytosol to synthesize membrane lipids

for the oxidation of fatty acids the 16 carbon palmitic acid undergoes how many passes though the oxidative sequence

7

throughout each pass of the oxidative sequence two carbon atoms are lost as what

acetyl coa

at the end of 7 cycles the last two carbon atoms (C-15,C-16) remain as what

acetyl coa

The overall result is the conversion of the 16-carbon chain of palmitate to

eight two-carbon acetyl groups of acetyl coa molecules

stage 1 of the oxidation of fatty acids

A long-chain fatty acid is oxidized to yield acetyl residues in
the form of acetyl-CoA. This process is called oxidation

stage 2 of the oxidation of fatty acids

The acetyl groups are oxidized to CO2 via the citric acid cycle

stage 3 of the oxidation of fatty acids

Electrons derived from the oxidations of stages 1 and 2 pass to
O2 via the mitochondrial respiratory chain, providing the energy for
ATP synthesis by oxidative phosphorylation

The single bond between methylene
(CH2) groups in fatty acids is

relatively stable

The b-oxidation
sequence is an elegant mechanism for
destabilizing and

breaking these bonds

in each pass through this... step sequence of the b-oxidation

4

one acetyl residue (shaded in pink) is removed in the form of ... —in this example palmitate (C16), which enters as palmitoyl-CoA

acetyl-CoA from the carboxyl end of the fatty acyl chain

Six more passes through the pathway yield ... , the seventh arising from the
last two carbon atoms of the 16-carbon chain. Eight
molecules of acetyl-CoA are formed in all

seven more molecules of acetyl-CoA

for the b-oxidation sequence 1 molecule of NADH and FADH2 give mow many molecules of ATP

3 and 2

Transfer of electrons from NADH or FADH2 to O2 yields one

H2O per electron pair

Reduction of O2 by NADH also consumes one

H+ per NADH molecule

The overall equation for the oxidation of palmitoyl-CoA to...

8 molecules of acetyl coa

In hibernating animals, fatty acid oxidation provides metabolic

energy heat water

One of the most pronounced adjustments of fat metabolism occurs in

hibernating grizzly bears

Hibernating grizzly bears use... as their sole fuel source

body fat

Fat oxidation yields sufficient energy for maintenance of

body temperature active synthesis of amino acids and proteins

The glycerol released by degradation of triacylglycerols is converted into blood glucose by

gluconeogenesis

Urea formed during breakdown of amino acids is reabsorbed in

the kidneys and recycled

Acetyl-CoA Can Be Further Oxidized in the

citric acid cycle

in aerobic respiration how much ATP comes from 1 molecule of glucose

32-36

in aerobic respiration 1 NADH and 1 NADH2 yield how much ATP

2-3 and 1-2

cancer cells are defined by 2 heritable properties

(1) they reproduce in defiance of the normal restraints on cell growth and division, and
(2) they invade and colonize territories normally reserved for other cells.

As long as the neoplastic cells have... invasive the tumor is benign

not invaded surrounding tissues

a tumor is considered a true cancer if it is malignant this is when its cells have the ability to

invade surrounding tissue

it is generally... that kill cancer patients

metastases

the doubling time of a typical breast tumor is about how many days

100

Knudsons two hit hypothesis

1. TSG mutation in a normal cell leading to a sporadic cancer
2. TSG mutation in a cell with a germline mutation leading to familial cancer

Tumor progression involves a large element of... and takes many years

chance

At each stage of cancer progression, some individual cell acquires an

additional mutation or epigenetic change

additional mutations or epigenetic changes in cancer cells give it a selective advantage over... making it better able to thrive in this environment

its neighbors

The environment inside a tumor, may be harsh,

with low levels of oxygen,
scarce nutrients, and
the natural barriers to growth

cancer cells have an altered sugar metabolism and ...

Warburg effect

Given sufficient oxygen, normal adult tissue cells will generally... in the glucose

fully oxidize almost all the carbon

a growing tumor needs...to provide the building blocks to...

nutrients in abundance , make new macromolecules

tumor cells consume ... avidly importing it from the blood at a rate that can be as much as 100 times higher than neighboring normal cells

glucose

in cancer cells, only a small fraction of this imported glucose is used for... by oxidative phosphorylation

production of ATP

since cancer cells only use a small fraction of glucose for ATP production a large amount of what is produced

lactate

what is the warburg effect

the tendency of cancer cells to de emphasize oxidative phosphorylation while taking up large quantities of glucose

in cancer cells many of the remaining carbon atoms derived from glucose are diverted for use as raw materials for the synthesis of... required for tumor growth

proteins, nucleic acids, and lipids

In the interior of a large solid tumor, cell... occurs on a massive scale

death

in tumor cells the living conditions are brutal with severe competition among the cancer cells for ...

oxygen and nutrients

many cancer cells will die but typically more die from ... than apoptosis

necrosis

large rates of cancer cell death are the reason for what

the time it takes for a tumor to double in size can be far longer than the cell cycle time of the tumor cells

cancer cells spread and multiple at new sites in the body through a process called

metastasis

what is the most deadly and least understood aspect of cancer which is responsible for 90% of cancer associated deaths

metastasis

Metastasis is a multistep process:

cancer cells first have to invade local tissues, move through circulation, leave the vessels and then establish colonies

the types of accidents that can convert a proto-oncogene into an oncogene from good to bad are what

1. deletion or point mutation in coding sequence
2. regulatory mutation
3. gene amplification
4. chromosome rearrangement

what systems does cystic fibrosis affect

respiratory and digestive

cystic fibrosis most seriously affects ... cells which increases the risk of infection by bacteria

lung

what are two distinct forms of cell death

necrosis and apoptosis

cells in ... seem to have exploded while cells in ... have condensed but relatively intact

necrosis apoptosis

characteristics of necrosis

inflammatory response, ATP independent