bio cards Flashcards
nucleolus
dense structure in nucleus, site of rRNA synthesis. not surrounded by membrane. after assembly, subunits exported to cytoplasm to help with protein synthesis.
mitochondria
“power house of cell”. outer and inner phospholipid bilayer. inner membrane has cristae and houses proteins of electron transport chain. inner membrane = matrix (low H+ concentration) intermembrane space - high H concentration contain own circular dna and ribosomes. can produce some proteins
endosymbiotic hypothesis
mitochondria believed to have developed from early prokaryotic cells and formed a symbiotic relationship with ancestors of eukaryotes. mitochondria provided energy and the host cell provided nutrients and protection from the exterior environment
Mitochondrial inheritance
zygote receives all organelles from mother - mitochondrial DNA is inherited from mother (identical to mother)
ribosome
responsible for protein synthesis. large and small subunit composed of rRNA and proteins - can be free or bound to endoplasmic reticulum.
free ribosomes
synthesize proteins destined for cytoplasm, found in the cytoplasm
bound ribosomes
bound to ER. synthesize proteins destined for insertion into membrane or secretion outside cell
Endoplasmic reticulum
interior membrane layer is lumen smooth er- no ribosomes on surface, involved in lipid synthesis and detox of drugs and poisons rough er - involved in protein synthesis small regions of er bud off to form vesicles with newly made protein - transported to golgi apparatus
golgi apparatus
stack of membrane enclosed sacs b/w ER and plasma membrane. modifies and sorts proteins.
lysosomes
break down proteins, carbs, and nucleic acid. slightly acidic inside (pH 5) important for degrading bacteria/foreign parts and degadation of damaged cells
peroxisomes
have oxidative enzymes. catalyze rxn in which hydrogen peroxide is produced and degraded break down fats detoxify alcohol in liver could damage DNA or other parts of cell if not compartmentalized
cytoskeleton
provide framework for maintenance of cell’s shape involve: microfilaments - 2 strands of actin, involved in muscle contraction along with myosin intermediate filaments - fibrous proteins coiled into thicker cables - structural support of a cell microtubules - hollow rods made of tubulin. involved in mvmt of organelles and chromosomes, maintenance of cell shape, cell motility
diffusion
passive transport, no energy required, CO2, O2 nonpolar transported goes from high to low gradient
osmosis
passive, no energy required transports H2O down gradient
facilitated diffusion
passive, no energy req. moves polar mol. and ions down gradient requires carrier molecules
active transport
active, requires energy low to high gradient transports proteins - Na/K pump
anaerobic cellular respiration
Glucose+2ATP + 4ADP +2 NAD+ + 2 Pi → Glycolysis → 2 Pyruvate + 2 ADP +4ATP+2NADH+2H++2H2O → Pyruvate +NADH+H+→ Fermentation → Ethanol (yeast) +CO2 + Lactic Acid + NAD+
aerobic cellular respiration
Glucose+ 2ATP + 4ADP +2 NAD+ + 2 Pi → Glycolysis → 2 Pyruvate + 2 ADP +4ATP+2NADH+2H++2H2O → 2 Pyruvate +2CoA+2NAD
NAD+ + FAD
coenzyme that can accept high energy electrons during glucose oxidation (come as H-).
atp generated from their stored energy - gathered through electron transport chain
- accept hydride ions during glycolysis and krebs cycle, reduced to NADH and FADH2
- carried through electron transport chain on inner mitochondrial membrane - liberated to produce ATP
- liberation causes oxidation to NAD+ + FAD
release of energy for ATP-ADP
7 kcal/mol
oxidation
LEO - loss of electrons is oxidation
reduction
GER - gain of electrons is reduction
determining oxidation state
consider electronegativity of bonded atoms treat molecule as ionic with more EN atom taking all the electrons solve for oxidation state using eqtn: # v.e. - # e around atom (after considering EN)
Bacteria
prokaryotic - no nucleus or membrane-bound organelles
viruses
can’t carry out metabolism outside of host cell
bacteriophages
viruses that infect bacteria
fungi
lack chlorophyll. eukaryotic, have membrane bound organelles
cytosol
continuous compartment inside prokaryotes
phospholipid bilayer
hydrophilic heads (on exterior) hydrophobic tail (interior).
transfer of genetic info in prokaryotes
transformation- DNA taken up from environment, integrated into bact. genome transduction - bact. genes transferred from one bacterial cell to another by a virus conjugation - direct transferred b/w bact. by conjugation bridge
autoradiography -
uses radioactive molecules to trace and id cell structures and localize biochem activity - used to find location of synthesis of viral proteins
facilitated diffusion -
uses protein channel to move large, polar molecules across membrane - doesn’t require energy
mitochondrial DNA
circular, self replicating. allos mito. to be semiautonomous. can synthesize some of their own protein and replicate with binary fission
ribosomal subunits in pro vs. eukaryotes
subunits are different pro: subunits are 30S and 50S, eu: 40S and 60S
Na+/K+ ATPase
moves 3 Na ions out for every 2 K ions into cell.
enzyme-catalyzed reaction
rate of rxn increased by decrease in activation energy. enzymes not changed or consumed during course of rxn. overall delta G (free-energy change of rxn) remains unchanged in presence of enzyme
enzyme activity conditions:
max activity for enzymes around 37 C and pH 7.4 (normal body fluid pH)
pancreatic enzyme optimal pH
basic. like alkaline conditions of small intestine
apoenzyme -
devoid of necessary cofactor - catalytically inactive
negative feedback -
by limiting the activity of enzyme 1, the rest of the pathway is slowed.
glycolysis
happens in cytoplasm, can be anaerobic total output - 4ATP, uses 2ATP
Glucose+2ADP+2Pi + 2NAD+ → 2 Pyruvate + 2ATP + 2 NADH +2 H+ + 2H2O
fermentation
glycolysis plus reduction of pyruvate
produces NAD+, no new ATP
alcohol ferm: in yeast and bacteria - pyruvate to ethanol and NAD+
lactic acid ferm: done when oxy demand higher than supply -2x as many molecules of pyruvate and NAD as glucose; NADH builds up and not enough NAD+ -pyruvate reduced to lactic acid, NADH-NAD+
Cori Cycle
lactic acid converted back to pyruvate. amt of oxygen required to do this = oxygen debt.
Cellular Respiration Equation
C6H12O6+6O2→6CO2+6H2O+energy
- series of redox reactions
- reverse of photosynthesis equation
- energy lost in heat
- O is final receptor in long electron transport chain
Pyruvate Decarboxylation
- first step in aerobic respiration
- pyruvate transported into mitochondria and loses CO2
- Acetyl-CoA is intermediate - key in using fat, protein, and carb energy reserves.
- forms NADH, Acetyl Co-A, and CO2
Citric acid cycle
aka Krebs, (TCA)
- 2nd phase of aerobic resp.
- each turn of cycle produces 1 ATP
- generates high energy electrons carried by NADH and FADH2
- 1 Acetyl- CoA generated 3 NADH and FADH2
- cycle turns twice per molecule of glucose
- produces: 6NADH, 2FADH2, 2 ATP - coenzymes transport electrons to ETC in inner mito membrane
electron transport chain
allows energy to be harnessed from carriers (NADH and FADH2)
- carriers in chain are cytochromes - 3 different ones (enzymes and last one is a protein)
- energy from NADH = 3ATP
- energy from FADH2 =2ATP
- production of energy relies on proton gradient across inner mit. membrane that links oxidation to phosphorylation of ADP.
– creates proton gradient with higher H concentration in intermembrane space. pushed passively back to mito membrane. energy release allows for phosphorylation of ADP to ATP.
oxidative phosphorylation
process where e from NADH and FADH2 are passed along between carriers that release free energy with each transfer - put towards ATP production.
where do events of respiration happen
glycolysis —- cytoplasm
fermentation —- cytoplasm
pyruvate to acetyl CoA —- mitochondrial matrix
TCA cycle —- mitochondrial matrix
Electron Transport Chain —- inner mitochondrial membrane.
Overall ATP production
Glycolysis:
-2 ATP
+4 ATP (substrate)
+4 ATP (oxidative)
=+6 ATP
Pyruvate decarboxylation
+ 6 ATP (oxidative) Krebs Cycle
+18 ATP (oxidative)
+ 4 ATP (oxidative)
+ 2 ATP (substrate)
=+24 ATP
TOTAL: +36 ATP
metabolism of carbs proteins and fats
protein = hydrolysis to amino acids to keto acids or pyruvate to krebs cycle carbs = hydrolysis to glucose to PGAL to pyruvate to acetyl CoA to krebs cycle fats = hydrolysis to glycerol or fatty acids to krebs cycle ** at the end of the kreb’s cycle they all end up as CO2
enzyme specificity
enzyme will only catalyze one specific reaction - acts on substrates, and substrate binds to active site of enzyme
factors that affect enzymes
pH - optimum is 7.2, activity declines above or below concentration of substrate and enzyme- if [enzyme] is limited, rate of rxn will level off even with more substrate because no more enzyme available to bind temperature - increased temp will increase rxn up to optimum temp. denatured at higher temperatures (won’t work at all) cofactors - non protein molecules required to make enzyme active
chromosomes in humans
23 chromo pairs, 46 total 1 chromo in each pair from mom and one from dad (in somatic and gametes)
Interphase/Cell phase
G1 and G2 - doubles cytoplasm and organelles; S synthesis, replication of DNA (still in form of chromatin)
S Phase
each chromosome is replicated prophase, metaphase, anaphase, telophase
prophase
chromatin condenses into chromosomes, spindle apparatus forms, nucleoli and nuclear membrane disappear
metaphase
chromosomes line up single file on equatorial plane and each one attaches to a separate spindle fiber by its kinetochore
anaphase
sister chromatids separate and migrate to the poles
telophase
2 cells formed; nuclear membrane formed around both nuclei; cytokinesis (division of the cytoplasm) occurs; two identical, diploid cells with single stranded chromosomes are formed.
meiosis
sexual reproduction - production of gametes. one round of replication and 2 rounds of division
chromosomes vs. chromatids
chromosomes - never fewer than 2n (46 in humans) chromatids - will have 92 right before mitosis
interphase I
same as mitosis - start with a diploid cell and double stranded chromosomes.
prophase I
chromatin condenses into chromosomes, spindle apparatus forms, nucleoli and nuclear membrane disappear; homologous chromosomes come together and overlap (synapsis); each chromosome has 2 sister chromosomes - called a tetrad (4 chromatids); homologous chromosomes exchange genetic material (genetic recombination/crossing over); genetic recombination promotes variation, therefore daughter cells not identical to parents
chiasmata
place where chromosomes are joined
metaphase I
homologous pairs line up along equatorial plate and attach to spindle fibers
anaphase I
homologous chromosomes are separated, move to opposite poles
disjunction
when homologous chromosomes are separated, move to opposite poles
nondisjunction
if chromosome pairs in anaphase I fail to separate - produces gametes with one extra or one less chromosome.
telophase I and cytokinesis
nuclear membrane forms around each nucleus. each chromosome at this point consists of 2 sister chromatids and a centromere. each cell reduced to haploid condition.
meiosis II
analogous to mitosis l at the end there will be 4 haploid cells which are different from parent cells, with single stranded chromosomes.
Oogenesis
oogonium (2n) - primary oocyte - meiosis I: secondary oocyte and first polar body - meiosis II: ovum and second polar body
spermatogenesis
speratogonium - primary spermatocyte - meiosis I: secondary spermatocytes - meiosis II: sperm cells (n)
fertilization
takes place in the fallopian tube. happens when sperm and egg come together in oviduct to produce a zygote (diploid-2n)
development of egg to diversified cells
fertilization to zygote to morula (solid ball of cells) to blastula (hollow ball of cells) then implantation occurs in the uterus - the blastula goes through gastrulation to gastrula (3 cell layers) to neurulation and the formation of neurula
what is formed from the ectoderm
nervous system (brain and spinal cord), epidermis, lens of eye, inner ear
what is formed from the endoderm
epithelial lining of digestive tract, lungs, liver, pancreas
what is formed from the mesoderm
muscle, skeleton, circulatory system, gonads, kidneys
placenta
site of exchange of food, oxygen, waste and water between the fetus and mother.
amnion
provides watery environment, prevents shock to embryo/fetus
umbilical cord
attaches embryo to placenta
chorion
membrane that surrounds the amnion
fetal circulation
blood is oxygenated in the placenta. the blood is shunted away from the developing lungs and liver by the ductus venosus, ductus arteriosus, and the foramen ovale. -umbilical vein carries oxygenated blood to the fetus from placenta
- inferior and superior vena cava return deoxygenated blood to the right atrium
- blood from umbilical vein and vena cava mix and blood entering right atrium is only partially oxygenated. most blood bypassses pulmonary circulation and enters left atrium directly from right atrium via foramen ovale
- pulmonary arteries carry oxy blood to the lungs but it isn’t saturated with oxygen
- in lungs, oxygen is unloaded
- deoxy blood returns to the left atrium via pulmonary veins and delivered to the rest of the circulatory system,
- deoxygenated blood is returned to the placenta via the umbilical arteries
foramen ovale
shunt in fetus that connects the right and left atria - blood entering the right atrium from the superior vena cava will flow into the left atrium instead of the right ventricle. pressure in the right atrium is higher so blood will spontaneously flow down gradient to the left atrium. - some blood still goes to right ventricle because that valve isn’t closed
ductus arteriosus
shnt in fetus that shunts leftover blood from the pulmonary artery to the aorta. works because the pressure in the right fetal heart is higher than in the left.
ductus venosus
reroutes blood returning from the placenta via the umbilical vein to the inferior vena cava. detours it from liver because liver has its own oxygen coming from arteries leaving the heart
umbilical veins and arteries
veins - carry blood towards the fetus (oxygenated) arteries - carry blood away from fetus (deoxygenated)
gas exchange in fetus
occurs in placenta not lungs
fetal respiration
fetus receives oxygen and disposes of CO2 at the placenta. facilitated by fetal hemoglobin, which has a higher affinity for oxygen than maternal hemoglobin
allele
one of a pair of genes
phenotype
outward appearance of a person with a given trait
genotype
genetic characteristics of an individual
Mendel’s Law of dominance
if 2 individuals with contrasting, pure breeding traits are crossed, dominant trait is expressed, recessive trait is hidden
Mendel’s Law of Segregation
every normal diploid organism has 2 alleles for each inherited trait. during meiosis, these segregate and form gametes that carry only one allele for a given trait. as a result in a monohybrid cross b/w 2 heterozygotes, the ratio of the offspring is 3:1 dominant:recessive
Mendel’s Law of Independent assortment
during meiosis, all allele combos are give to gametes w/ equal probability (distribution has no effect on others if the genes are unlinked). In a dihybrid cross for unlinked traits 1 and 2, the ration of the offspring is 9 (dominant for both):3 (dominant for 1, R for other): 3 (vice versa):1 (recessive for both)
autosomal recessive inheritance
usually both males and females affected. if it skips a generation it is recessive
autosomal dominant inheritance
if autosomal usually both males and females affected. in general, if it doesn’t skip a generation it is dominant
X-linked or sex linked recessive inheritance
if X linked - there will usually be more affected males than females. no male-male transmissions
blood types
A - anti-B antibody; A antigen, can donate to A and AB, can receive from A and O B: anti-A antibody; B antigen; can donate to B and AB, can receive from B and O AB: no antibodies, A and B antigens; can donate to AB, can receive from A, B, AB, and O O: anti-A and anti-B antibodies; no antigens; can donate to A, B, AB and O, can receive from O
bacteria cell wall
made of peptidoglycan
fungi body
net like mass of filaments called hyphae, many hyphae make up a mycelium.
when do secondary oocytes complete meiosis II
when they are fertilized by a sperm.
when do primary oocytes complete meiosis I
during puberty, one primary oocyte a month completes meiosis I and creates a secondary oocyte and polar body. secondary oocyte is expelled from the follicle during ovulation
when does menstruation occur (hormonal influence)
sudden reduction in the level of secretion of estrogen and progesterone. occurs approximately 2 weeks after ovulation
progesterone
essential for maintenance of the endometrium - drop in progesterone causes endometrium to slough off in menstruation
endometrium
innermost lining of uterus. maintains patency of uterine cavity. during menstruation - endometrium becomes thick with lots of blood vessels - optimal for blastocyst. during pregnancy - will become placenta.
FSH
follicle stimulating hormone - gonadotropic hormones secreted by anterior pituitary gland. causes maturation of ovarian follicles
LH
luteinizing hormone - gonadotropic hormone secreted by anterior pituitary gland. stimulates ovulation and formation of corpus luteum
corpus luteum
involved in production of progesterone. helps encourage secretion of LH and FSH
functions of the placenta
nutrient, gas, and waste exchange occurs higher oxygen pressure in maternal blood than fetal blood so the oxygen diffuses from the mom to the fetus.
serves as a barrier to prevent mixing of fetus and mother’s blood - immune [rptectopm - produces progesterone, estrogen, and hCG to maintain pregnancy - can’t prevent viruses, alcohol, and toxins from getting to fetus.
times when first second and third cleavages occur in embryo
32, 60, and 72 hours postfertilization. at third cleavage - eight celled embryo has gotten to uterus
morula
“mulberry” solid mass of cells
blastula
forms after morula through blastulation. have hollow, fluid-filled inner cavity.
known as blastocyst in mammals
settles in uterine wall and implants in endometrium progesterone promotes implantation
gastrula
happens once the cell mass implants. generation of 3 distinct cell layers forms hollowed out cup shape
- inside cup becomes endoderm, outside of cup becomes ectoderm and layer inside is mesoderm.
notochord
rod of mesodermal cells
- forms along long axis of the forming fetus
development of adrenal glands
adrenal cortex is derived from mesoderm
adrenal medulla is derived from ectoderm because it contains some nervous tissue.
