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?
glycolipids are found where?
membranes and myelinated cells (nervous sys.)
4 ring structure
examples of categories of steroids
hormones, vitamin D, cholesterol
how are fats trasnported through the blood?
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
acrylamide, urea, hight temp.
do nucleic acids have H bonds and tertiary and quaternary structures?
how do plants store glucose? animals?
plants = cellulose and starch
animals = glycogen
animals can digest what forms of stored glucose?
starch and glycogen
In glycolysis, is glucose oxidized or reduced?
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?
written in what direction?
5' > 3'
are minerals organic or 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?
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?
how much ATP and NADH produced in glycolysis?
how much ATP is produced in glycolysis for prokaryotes?
does glycolysis req. O2?
is glycolysis reversible?
exception: liver makes glucose from glycogen
Pyruvate Dehydrogenase complex
forms acetyl group + co-enzyme A (acetyl-coA)
How many ATP and NADH molecules are produced by Pyruvate dehydrogenase complex?
where does Pyruvate Dehydrogenase complex occur?
mitochondrial intermembrane space
where does Krebs cycle occur
ETC also known as...
ultimate acceptor of e- in ETC
How many ATPs produced per NADH molecule?
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?
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
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?
what happens first in replication?
DNA helicase unwinds double helix
after unwinding.... DNA polymerase
builds new DNA strands
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?
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?
How are Okazaki fragments brought together?
Is DNA replication proofread?
Yes, thats why its accurate
- 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
- 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?
in what direction does RNA polymerase move?
moves along 3' to 5'
builds 5' to 3'
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?
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?
43 = 64 possibilities; but only 20 amino acids
Can more than one sequence code for the same amino acid?
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
tRNA anticodon that initiates translation
CAU (complementary to codon)
large subunit joins joins after CAU sparks A
2nd tRNA attaches to A site with anticodon to first nucleotide
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
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
change in a single base pair of nucleotides
examples of point mutation
missense and nonsense mutation
change in codon that codes for a different amino acid than original
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
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
haploid and diploid
what does n represent?
haploid = n, diploid = 2n
n = # of chromosomes
how many chromatids in n chromosomes?
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?
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
division without genetic change
condensation of chromatin into chromosomes
chromosomes align along equator of the cell
sister chromatids split and attach to centromoeres
nuclear membrane forms
product of mitosis
2 identical daughter cells
microtubule organizing center,
at each side only in eukaryotes
spot where chromosomes are attached
attaches to spindle via kinetochore
2 haploid gametes
(involves 2 divisions)
what are the only cells that undergo meiosis?
only speratogonium and oogonium
homologous chromosomes line up
(may cross over)
site of crossing over
homologues align along metaphase plate
separate homologues from their partners
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?
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?
In what phase does the nuclear membrane disintegrate?
when chromosomes condense