-
catabolic v. anabolic
- catabolic = break down
- anabolic = build up
-
saturated v. unsaturated
- saturated = single bonds
- unsaturated = double bonds
-
which is more fluid membrane, saturated or unsaturated?
unsaturated
-
glycolipids are found where?
membranes and myelinated cells (nervous sys.)
-
steroids (structure)
4 ring structure
-
examples of categories of steroids
hormones, vitamin D, cholesterol
-
how are fats trasnported through the blood?
lipoproteins
-
structure of amino acid
H2N - CHR - COOH
-
4 structures of protein
- 1 - amino acids (peptide bonds)
- 2 - folding (H bonds)
- 3 - 3D shape (covalent disulfide bonds)
- 4 - many protiens
-
a-helix and b-sheet
- a-helix: twist
- b-sheet: lie alongside each other
-
denaturization disrupts what structure?
2o, 3o, and 4o
-
denaturing agents
acrylamide, urea, hight temp.
-
do nucleic acids have H bonds and tertiary and quaternary structures?
yes
-
how do plants store glucose? animals?
plants = cellulose and starch
animals = glycogen
-
animals can digest what forms of stored glucose?
starch and glycogen
not cellulose!
-
In glycolysis, is glucose oxidized or reduced?
oxidized
Glucose + O2 > H2O + CO2
-
3 components of nucleotides
- 1. 5C sugar
- 2. A,T,C,G,U (nitrogenous base)
- 3. Phosphate group
-
how are nucleotides joined?
phosphodiester bonds
-
written in what direction?
5' > 3'
-
are minerals organic or inorganic?
inorganic
-
what do minerals do?
assist in transport in/out of cells
act as cofactors
-
Km for enzyme reaction rate represents
[S] at 1/2Vmax
-
cofactors proteins or nonproteins?
nonproteins
-
competitive inhibition affects on Vmax and K
increase in Km but not Vmax
-
noncompetitive inhibition affects on Km and Vmax
Vmax is lowered
Km is unchanged (substrate can still bind to another enzyme)
-
competitive and noncompetitive inhibition - are they temporary or permanent?
competitive = temporary
noncompetitive = permanent
-
How can noncompetitive inhibitors be eliminated?
through metabolism and excretion
-
Overall aerobic metabolism (what's going on?)
1. glucose is oxidized - NAD+ is reduced
2. energy in these e- is used to pump H+ out - creating a proton gradient
3. proton gradient drives ATP production
-
what is so special about NAD+ that it can oxidize glucose?
high-energy e- carrier
-
How much ATP is produced by 1 NADH and 1 FADH2 molecule?
1 NADH = 2.5 ATP
1 FADH2 = 1.5 ATP
-
where does glycolysis occur?
cytoplasm
-
how much ATP and NADH produced in glycolysis?
2 ATP
2 NADH
-
how much ATP is produced in glycolysis for prokaryotes?
5 ATP
-
does glycolysis req. O2?
no
-
is glycolysis reversible?
No
exception: liver makes glucose from glycogen
-
Pyruvate Dehydrogenase complex
decarboxylates pyruvate
forms acetyl group + co-enzyme A (acetyl-coA)
-
How many ATP and NADH molecules are produced by Pyruvate dehydrogenase complex?
0 ATP
2 NADH
-
where does Pyruvate Dehydrogenase complex occur?
mitochondrial intermembrane space
-
-
where does Krebs cycle occur
mitochondrial matrix
-
ETC also known as...
oxidative phosphorylation
-
ultimate acceptor of e- in ETC
oxygen
-
How many ATPs produced per NADH molecule?
2-3 ATP
-
pH relativity in the matrix during ETC
innermembrane spaces has a lower pH than the matrix
-
fermentation uses what as final e- acceptor in ETC?
pyruvate
-
what happens to NADH in fermentation
recycled back to NAD+
-
products of fermentation
yeast and microorganisms = ethanol
muscle cells = lactic acid
-
net ATP production for aerobic and anaerobic respiration?
aerobic = 30 ATP
anaerobic = 2 ATP
-
How many copies of each gene do prokaryotes and eukaryotes have?
prokaryotes = 1 copy
eikaryotes = several copies
-
human genome
26,000-38,000 genes
-
purines and pyridines
purines = A and G
pyridines = C, U, T
"cut a pyramid"
-
number of H bonds between A, T, C, G
- A-T = 2 H bonds
- C-G = 3 H bonds
-
What bonds two nucleic acids together, and where?
phosphodiester bonds between 3C and 5C of sugar
-
DNA sequence (what is the chain?)
Pgroup + 5C sugar + N base
-
-
replication begins where?
middle of chromosome
-
-
what direction is replication?
bidirectional
-
what happens first in replication?
DNA helicase unwinds double helix
-
after unwinding.... DNA polymerase
builds new DNA strands
-
RNA primer
initiates the strand, so DNA polymerase can add nucleotides, creating the complementary strand
-
DNA polymerase reads and synthesizes in what direction?
reads 3' - 5'
synthesizes 5' - 3'
-
How does new nucleotide being added remove P-P?
hydrolysis
-
What drives the replication, energetically?
energy released in hydrolysis of P-P
-
Why lagging strand?
since DNA polymerase can read only in 1direction, and there are two strands, so 1 strand is looped around (flipped)
-
so why is lagoons strand lagging?
flipped reading causes interruption
restarts with a new primer
-
What are lagging interruptions called?
Okazaki fragments
-
How are Okazaki fragments brought together?
DNA ligase
-
-
Is DNA replication proofread?
Yes, thats why its accurate
-
Replication Summary
- 1. Helicase unzips double helix
- 2. RNA Polymerase builds a primer
- 3. DNA Polymerase assembles leading&lagging strand
- 4. Primers are removed
- 5. Okazaki fragments joined by DNA ligase
-
RNA versus DNA nitrogenous bases: U and T
DNA binds A to T
RNA binds A to U
-
How are DNA and RNA produced?
DNA produced by replication
RNA produced by transcription
-
Where are DNA and RNA found?
DNA: nucleus and mitochondrial matrix
RNA: cytosol
-
Transcription (summary)
- 1. initiation
- 2. RNA polymerase unzips DNA helix
- 3. Elongation
- 4. Termination
-
What is a promoter?
sequence of DNA that designates start of transcription
-
Elongation: RNA polymerase transcribes one or both strands of DNA?
both
-
in what direction does RNA polymerase move?
moves along 3' to 5'
builds 5' to 3'
-
transcription proofreading
no
-
termination
terminating sequence to dissociate RNA polymerase
-
What are activators and repressors?
bind to DNA close to promoter -
activate or repress activity of RNA polymerase
-
post-transcription processing: eukaryotes or prokaryotes?
both
-
What is involved in post-transcriptional processing
primary transcript is modified
- 5' end is capped
- 3' end adds poly-A tail
primary transcript is cleaved
-
How is primary transcript modified?
- addition of nucleotides
- deletion of nucleotides
- modification of nitrogenous bases
-
How is primary transcript cleaved?
sNRPs loop out introns, uniting exons
-
what happens to introns and exons
introns remain in the nucleus
eons join together to make mRNA - which will be translated
-
Are there more codons or amino acids?
codons
43 = 64 possibilities; but only 20 amino acids
-
Can more than one sequence code for the same amino acid?
Yes
-
What are the stop and start codons?
start = AUG
stop = UAA, UGA, UAG
-
Roles of mRNA, tRNA, rRNA
mRNA = carries genetic code from nucleus to cytosol
tRNA = contains antidocodon
rRNA = makes up ribosome
-
ribosome: prokaryotic v. eukaryotic
prokaryotes = 30S + 50S = 70S
eukaryotes = 40S + 60S = 80S
-
Which side attaches to small ribosomal unit
5'
-
tRNA anticodon that initiates translation
CAU (complementary to codon)
-
Translation initiation:
large subunit joins joins after CAU sparks A
-
translation: elongation
2nd tRNA attaches to A site with anticodon to first nucleotide
continues on...
-
translation: termination
stop codon is reached along mRNA
-
when stop codon reaches A site, how does it terminate the translational process?
release factor binds to A site
adds water to end of polypeptide chain - releases new protein
-
post-translational process
sugars, lipids, P groups can be added to protein
-
translation and ER
translation can occur free in cytosol
or in ribosomes that attach to ER
-
fate of proteins translated in ribosomes on rough ER
secreted from cell (via golgi)
remain partially attached to the membrane
-
point mutation
change in a single base pair of nucleotides
-
examples of point mutation
missense and nonsense mutation
-
missense mutation
change in codon that codes for a different amino acid than original
-
nonsense mutation
mutates to a stop codon
-
point mutation affect on protein
missense: alters protein function
nonsense: loss of protein function
-
insertion or deletion mutation examples
frameshift: adding/deleting not in multiples of 3
nonframeshift: add/delete in multiple of 3
-
mutation in somatic or germ cells are passed on to offspring
somatic
-
What is a chromosome?
2 sister chromatids attached at a centromere
-
outline of chromosome
DNA - cental - histones - chromatin -(supercoil)- chromosome
-
crossing over takes place in
prophase I
-
haploid and diploid
what does n represent?
haploid = n, diploid = 2n
n = # of chromosomes
-
how many chromatids in n chromosomes?
2n chromatids
-
What are homologues?
chromosome partners that code for the same traits
but they're different genes
-
Are diploid and haploids homologous pairs?
diploid, but not haploid
-
What is the structural unit of a chromosome?
nucleosome
-
electrophoresis: charge of anode and cathode
in what direction does nuclide move?
anode = (+) cathode = (-)
(-) from P group attracted to (+) anode
-
-
In what phase is liver and intestines?
liver divides once/year - G0 phase
intestine divides twice/day
-
mitosis
division without genetic change
-
Prophase
condensation of chromatin into chromosomes
-
Metaphase
chromosomes align along equator of the cell
-
Anaphase
sister chromatids split and attach to centromoeres
-
Telophase
nuclear membrane forms
-
product of mitosis
2 identical daughter cells
-
centrosome
microtubule organizing center,
at each side only in eukaryotes
-
centromere
spot where chromosomes are attached
attaches to spindle via kinetochore
-
meiosis produces
2 haploid gametes
(involves 2 divisions)
-
what are the only cells that undergo meiosis?
in humans?
germ cells
only speratogonium and oogonium
-
Prophase I
homologous chromosomes line up
(may cross over)
-
site of crossing over
chiasma
-
Metaphase I
homologues align along metaphase plate
-
Anaphase I
separate homologues from their partners
-
Telophase I
nuclear membrane and cytokinesis
-
so, what is meiosis II?
same as meiosis I but doubled
-
products of meiosis
haploid gametes with 23 chromosomes
-
What is nondisjunction?
centromere doesn't split in anaphase
-
Nondisjunction in anaphase I
once cell = 2 extra chromatids
other cell = missing 2 chromatids
-
Nondisjunction in anaphase II?
one cell has 1 extra chromatid
*will behave normally in meiosis
-
Where do primary spermatogonium/oogonium come from?
product from S phase in Interphase
-
When does female (oogonium) life cycle begin?
starts at birth
stuck in Prophase I until puberty
-
just before ovulation, primary oocyte does what?
undergoes mitotic division -
becomes 2o oocyte
-
when is the 2o oocyte released?
upon ovulation
-
what does penetration of 2o oocyte by sperm do?
stimulates anaphase II
-
summary of oogonium reproduction
- 1. stuck in prophase I
- 2. puberty = stimulates life cycle
- 3. meitotic division just before ovulation (2o)
- 4.penetration of 2o oocyte by sperm stimulates anaphase II
-
When is primary speratocyte produced? Is it haploid or diploid, and how many chromosomes does it have?
just after DNA replication
diploid, 46 chromosomes
-
What does DNA ligase do?
unites interrupted DNA fragments
-
Is prokaryotic DNA single or double stranded?
double stranded
circular
-
In what phase does the nuclear membrane disintegrate?
Prophase
when chromosomes condense
|
|
