Biology Flashcards
microfilaments
- ACTIN (use myosin + ATP for movement)
- also in cytokinesis to contract cell
microtubules
- hollow polymers of tubulin
- uses kinesin + dynein to carry vesicles in cell
- cilia/flagella = in eukaryotic motile cells
- centrioles = in centrosome, organizing centre for microtubules
intermediate filaments
- cell-cell adhesion, integrity, resist tension, anchor
- ketatin, lamin, desmin, etc.
archaea
- single cells, look like bacteria but eukaryotic function
- circular chromosome, binary dfission
- eukaryotic: wrap DNA with actual histones, begin with Met, RNA polymerase same
types of bacteria metabolism
obligate aerobes
obligate anaerobes
facultative anaerobes
aerotolerant aerobes
3 types of bacterial genetic recombination
transformation = integrate foreign DNA with plasmids
conjugation = mating (donor, female)
transduction = need VECTOR, virus transports DNA/RNA
positive sense VS negative sense viral genome
positive sense = ssRNA directly translated
negative sense = ssRNA make complementary strand first (RNA replicase)
viral life cycle:
- infection
- translation/assembly
- progeny release
lytic (virulent) VS lysogenic (dormant, integrate provirus into genome)
prions
nonliving infectious proteins
convert alpha helix > beta sheet, protein aggregates
viroids
small pathogens living in plants, bind RNAs + silence genes
cell cycle overview
- G1 = least amount of DNA, increase size, grow organelles
- G1/S checkpoint = make sure DNA good to replicate p53
- S = replicate DNA ploidy doesn’t change, 2n»2n
- G2 = more growth
- G2/M checkpoint = ensure all organelles, cytoplasm, correct DNA replication
mitosis vs meiosis
- 2n>2n VS 2n>n
- meiosis I similar to mitosis, but meiosis II very different
- crossing over in meiosis
- homologous chromosomes pair in meiosis
nondisjuction in meiosis I
causes two n-1 cells and two n+1 cells
all 4 gametes abnormal ploidy
nondisjunction in meiosis II
only 2 gametes affected, 2 normal
one n-1, one n+1
order of sperm flow
SEVE(N) UP
oogenesis
- each oogenia = ONE functional oocyte
- primary oocytes born with 2n, arrested in prophase I (meiosis)
- during ovulation, meiosis I –> secondary oocyte (n) –> fertilization –> meiosis II
2 layers of oocyte
zona pelucida = surrounding oocyte, proteins + compounds
corona radiata = surrounding cells, attached to oocyte
male sexual development
- androgens during fetal period causes male sexual differentiation
- testosterone = develops reprod. system and secondary sex characteristics
- FSH stimulates sperm maturation
- LH causes testosterone production
female sexual development
- estrogen secreted due to FSH, secondary sex charaxcteristics
- estrogen regenerates uterine lining, but progesterone (secreted by corpus luteum) maintains it
menstrual cycle:
- follicular phase = GnRH releases LH/FSH, develops follicles, estrogen thickens lining
2. ovulation = LH PEAK - luteal phase = released follicle forms corpus luteum, secretes PROgesterone to develop lining – high est/progest = low LH/FSH
- menstruation = high progesterone buildup causes low LH, uterine layer shed, corpus luteum no longer to secrete est/progest, so causes GnRH to be stimualted again (low LH = corpus luteum lost)
- pregnancy = blastocyst releases hCG (analog of LH) that maintains corpus luteum
cortical reaction
after sperm penetrates egg, relese of Ca+ ions
depolarizes egg membrane to prevent another sperm, increases metabolic rate
blastocyst
ICM (becomes organism) and trophoblast (placenta)
gastrulation: 3 primary germ layers
- ectoderm = NS, hair, skin, nails
- mesoderm = support structures, muscle, bone, excretory, circulatory, gonads
- endoderm = epithelial linings, pacreas, thyroid, bladder
fetal circulation
- fetal arteries = DEOX blood from fetus to placenta
- fetal veins = OX blood from placenta to fetus
- gas exchange occurs at the placenta
- don’t want baby’s blood and mothers to mix
- detoxification by mother’s liver, nutrient/waste exchange at placenta
- 3 shunts
fetus: 3 shunts to direct blood away from its organs
- foramen ovale RA-LA = blood skips Right ventricle to bypass lungs, directly into body
- ductus arteriosus = shunts blood in pulmonary artery to aorta
- ductus venosus = shunts blood from placenta (umbillical vein) to inferior vena cava (bypass liver)
3 trimesters: overview
- heartbeag 22 days, 8 weeks = fetus, organ systems made
- growth, moves
- growth, LESS movement, antibodies transferred
specific neuroglia
- support / defense / immune system
- astrocytes = BBB
- microglia = break down waste products
- oligodendrocytes (CNS) and schwann cells (PNS)
action potential notes
- resting potential = -70mV (inside)
- cells = salty bananas
- Na+/K+ ATPase = “pumpKin” to restore balance
- axon hillock = threshold, trigger zone, voltage gated Na+ channels open
- hyperpolarization = refractory period prevents another signal
- local anesthetics block Na+ channels preventing pain impulses
- end of axon, Na+ channels open, Ca+ rushes in, NT vesicles released, enter synapse
reflex arc
- only processing at spinal cord level
peptide hormones
- bind EXTRACELLULAR, trigger cAMP signalling cascade
- end in “in” “ine”
- rapid but short-lived
steroid hormones
- bind INTRACELLULAR receptors
- cholesterol-based, cross membrane
- “one” “oid”
- slower but long-lived
AA hormones
- unpredictable
- catecholamines = fast lived, short lived (peptide-like)
- T3/T4 = slow onset, long lived (like steroid)
tropic hormones
stimulate production of another hormone by another gland that acts on a tissue, eg. ACTH
pituitary gland
- anterior = vascular connection (HTHPP): GH, TSH, FSH, LH, ACTH, PRL
- posterior = neural connection (tract): store + release oxytocin + ADH from hypothal.
thyroid
- controlled by TSH, T3/T4 = metabolism
- calcitonin = tones down Ca+
- PTH = increases Ca+
3 types of corticosteroids in adrenal cortex (sugar, salt, sex)
- glucocorticoids = cortisol (raise blood sugar)
- mineralocorticoids = aldosterone (increase Na+/H2o reabsorption to increase BV and BP)
- corticak sex hormones = androgens/estrogen
aldosterone pathway
- low BP sensed by juxtaglomerular cells
- cells secrete RENIN – celaves angiotensin to angiotensin I
- ACE converts angiotensin I to angiotensin II
- angiotensin II stmulates adrenal cortex to release aldosterone to increase BP
adrenal medulla
- ectoderm, NS, fast acting, not essential for life
- catecholamines (E, NE) – sympathetic fight/flight
pancrease cells
alpha = glucacon
beta = insulin (destroyed in type I, low receptor sensitivity in type II)
delta = somatostatin (inhib. both insulin + glucagon), reelesed by high BG/AA’s
pineal gland
secretes melatonin
circadian rhythms
EPO
released by kidneys
production of RBC’s
ANP
released by the heart
regulates salt/water balance
promotes excretion, deceases BV and BP
types of steroid hormones: list
- cortical hormones (all)
- testosterone, estrogen, progesterone
types of AA hormones: list
- T3/T4
- any other hormone is a PEPTIDE hormone
diaphragm is under ____ control
somatic control
but breathing is autonomic
surfactant
on alveoli
REDUCES surface tension
prevents collpase of alveoli during exhalation
negative pressure breathing
diaphragm contract, pulls downwards, increase V, decrease P, air sucked in from low pressure
total lung capacity
max volume of air in lungs
residual volume
air left in lungs after complete exhalation
vital capacity
air volume inhaled/exhaled in normal breath = tidal voume
VC = tidal volume + expiratory/inspiritory reserve
expiratory/inspiritory reserve
additional air forced out/inhaled
heart: blood flow order
vena cava > RA > tricuspid > RV > pulm valve > pulmonary A > lungs > pulmonary V > LA > bicuspid/mitral > LV > aortic valve > aorta
heart sounds
1st pump: AV valves close – RV contracts = pulmonary circulation
2nd pump: semilunar valves close – LV contracts = systemic circulation
electrical conduction in heart: order
SA node > AV node > bundle of His > purjunke fibres