Notes

molecules in the cytoskeleton - made of protein dimers
microtubules - form cilia and clagella
microfilaments - thin rods of actin , smallest of the 3, allows stretching or compression, cell adhesion
microtubules corm cilia and flagella
microfilaments - thin rods of actin ,smallest of the 3, allows stretching or compression, cell adhesion
intermediate fibers - between in size, rare, found along basement membrane of skinl, adheres skin to connective tissue underneath it
epidermolysis bullosa - intermediate fibers fail and skin falls off
spherocytosis - cytoskeleton malfunction in RBC-causes rbcs to balloon out blocking blood vessels especially in the spleen. the spleen destroys the RBC's faster than the marrow can replace. anemia and fatigue result.
somatic cells undergo mitosis which produces exact geneetic copies of the original parent cell....
apoptosis - planned cell death, happens because some cells need to die to make room for the new cells
the cell cycle
INTERPHASE - G1 - cell grows, # or ogranelles doubles. some cells will exit G1 and go to G0 where they just exit the cell cycle and are no longer actively dividing like muscle cells, nervous cells, nerve cells, liver cells , most cells go to S phase - synthesis phase
S phase - synthesis phase - DNA replicates, after replication, there are 2 chromosomes, each chromosome is made up of 2 identical sister chromatids which are attached in the middle by a centromere - centrioles replicate...
G2 - Gap 2 phase - materials necessary for cell division are assembled
MITOSIS - division of nucleus, NOT part of interphase - has 4 phases
prophase - chromatic coils and condenses into visible chromosomes, nuclear envelope breaks down, nucleolus breaks down, centrioles migrate toward the poles, spindle beings to form
metaphase - spindle is fully formed, centrioles are at the poles, spindle fibers attach to the kinetochores, chromosomes line up at the equator
anaphase - spindle fibers shorten or lengthen, the ones that get shorter pull the sister chromatids apart the ones that lengthen elongate the cell so it can pinch in telophse, centromeres split, chromosomes move toward opposite poles, most rapid phase of mitosis
telophse - kind of the opposite of prophase, nucleolus reforms, nuclear membrane returns, chromosomes uncoil and become chromatin again
cytoinesis - division of the cytoplasm. in a plant cell the cell walls prevent the cell from pinching in so they take vesicles from the golgi which line up at the equator and form the cell plate, eventually the old cell membranes will form the cell walls of the new cells....animal - cleavage furrow, cell membrane invaginates - pinches inwards
regulation of cell division - too little - not enough cell reproduction
too much - cancer - cancer is the uncontrollled regulation of cell divison

how does a cell "know" how many divisions have taken place and how may remain? TELOMERES! - telomeres are chromosome tips....cellular "fuse" that shortens each time a cell divides....telomeres have hundreds to thousands of repeats of a specific 6 nucleotide RNA sequence. each time hte cell divides, RNA nucleotides are lost...telomerase allows males to produce sperma ll their lives once they go through puberty. telomerase prevents the telomeres from getting shorter

apoptosis - programmed cell death - cell rapidly and neatly dismantles itself into membrane bound "garbage bag" that can be mopped up by phagocytes
begins when the doomed cell's "death receptor" receives a signal to die
states of apoptosis - caspases are relased which
destroy the cytoskeleton that supports the nucleus - nucleus collapses and DNA condenses, destroy enzymes that replicate and repair DNA, activate enzymes that "chew up" DNA into small packages, tear apart the remainder of the cytoskeleton, destroy the cells ability to adhere to other cells, sned a specific phospholipid from the interior of the cell membrane to the exterior - this is a signal for cphagocytes to "come eat me"
destoy the cytoskeleton that supports the nucleus - nucleus ollapses and DNA condenses, destroy enzymes that replicate and repair DNA, activate enzymes that "chew up" DNA into small packages, tear apart the remainder of the cytoskeleton, destroy the cells ability to adhere to other cells, sned a specific phospholipid from the interior of the cell membrane to the exterior - this is a signal for phagocytes to "come eat me"
STEM CELLS
all cells have a complete set of genetic info. whencells differentiate, how od they know what they are to become?:
stem cells - undifferentiated cells that can become pretty much anything thye want to be,.....any speciifc tissues they wil become
cell differentiation based on potential
totipotent - capable of yielding daughter cells that can become any cell type. only example is a fertilized egg.....then it undergoes mitosis and becomes a group of pluripotent cells
pluripotent - cells early in the development process tha can yiled daughter cells that can differentiate into many, but not all, cell types.
progenitor - cells are committed to developing into a specific type of cell
totipotent - capable of yielding daughter cells that can become any cell type. fertilized egg is only example.
totipotent, pluripotent, progenitor
stem cels harvested from the umbilical cord can treat several disorders. sometimes embryonic stem cells can crossp lacental barrier and get into mom....coman with hepatitic C whose liver healed itself. biopsy revealed all new cells were XY and identical to newborn son...
XY cells have often been found in bloodstream of women who have male offspring
hematooietic stem cells - microchimerism
hematopoietic stem cells - stem cells that generate red blood cells RBC can be removed from bone marrow of cancer patientts
viruses and prions - virus - NOT ALIVE because they can't reproduce on their own.
virus injects its DNA or RNA into some of the human's cells causing the cells its injected into begin making viral nucleic acids and viral proteins hindering the cells from performing their intended jobs
infected cell is directed by the virus to make viral DNA and viral proteins and the cell does not preform regular activities
new viruses are created - cell bursts and ivruses are free to roam your vulnerable little insides
Prion - glycoprotein that can change shape and begin a chain reaction in the brain that causes other prions to begin to chnage shape
when they start making holes in your brain it's called "transmissible spongiform encephalopathy"
TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHY - occurs in 85 types of mammals
brain shot full of holes ; mad cow disease owas a form of this disease that was transmissible to humans
Kuru - tremble - found in a tribe in remote New Guinea
women and children would get a form of mad cow disease because they would butcher the meats and cut themselves ....then more people wudl eat the mad cow meat and get the disease..
genome - the complete genetic make-up of an organism
mutation - a change in a gene's DNA sequence
one way that genetic diseases differ from other diseases is presymptomatic testing is possible
A and a could represent alternate alleles of the same gene
the closer the nucleotide sequences for a particular gene in two different species, the more closely related those species are to each other
the close the nucleoteide sequences for a particular gene in two different species, the more closely related those species are to each other
energy is converted into a form that the cells can use in mitochondria
the lipid, protein, and carbohydrate components of cellular membranes are assembled in the Golfgi complexes ....everythin that is made by the endoplasmic reticulum gets finished in the golgi
spherocytosis (when RBC's blow up) is an inherited disease that primarily affects the cytoskeleton
apoptosis is progrmamed cell death
telomeres are chromosome tips
somatic (body) cells of a given species generally contain equal amounts of DNA
lysosome is n organelle that breaks down and recycles macromolecules
phases of mitosis - prophase, metaphse, anaphase, telophase
things in the cytoplasm of eukaryotic cells - ribosomes, endolasmic reticulum, mitochonnrdiria, mircotubules....chromatin is in the nucleus NOT the cyltoplasm
amino acids are assembeld into proteins in/on the ribosomes
lysosomes are membranous sacs containing hydrolytic enzymes
normal yeast cells have 4 chromosomes. at the end of mitosis, each daughter cell contains 4 chromsomes
advantages of GMO - more nutrients and vitamins, can make them grow faster, produce proteins that destroy insect pests
disadvnatages of GMO - sometimes they don't have seeds so they can't reproduce, allergies, effect on the environment,
functions of the cytoskeleton - anchor organelles, allow cell to move, cell division, highways, shape
4 functions of embedded macromolecules in cell membranes
are receptors - receive signals and send them through the membrane
channels to allow polar molecules to let them go through something
ID badges - ID the cell as being part of that organism
allow cells to adhere to each other
functions of embedded proteins
receptors - receive stimuli and send it either into or out of the cell
cell adhesion - cells like to stick together
id badges - there are some cells that only check the id badges on eaceh cell
channels - like the cylinder within a toiilet paper roll, allow polar molecules to let them go through somethign

CHAPTER 3
gemete - reproductive cell haploid - half the number of chromosomes that regular cells have
gonads - reproductive cells of female and male collectively

male reproductive system
testis - generates sperm and testosterone - housed in a scrotum
scrotum sac - temerature regulation
epididymis - where sperm gains mobility
vas deferens - sperm transportation
seminal vesicle - 1. add fructose to the sperm cells, energy for the sperm cells 2. prostaglandins
prostate gland - stimulates sperm cells to swim, helps neutralize fluid in female reproductive tract that is usually acidic
bulbourethral cland - prodcuing lubricating fluids that facilitate penis entering vagina
TSEVSPB
testis - generates sperm
scrotal sac - houses testes, temperature regulation,
epididymis - where sperm gain mobility
vas deferens - sperm transportation
seminal vesicles - add frucose to sperm, energy for sperm, prostaglandins which cause smooth muslces in female reproductive tract to contract,
prostate gland - stimulate sperm to move, neutralize acidicc fluids of female reproductive tract
bulbourethral gland - produce lubricating fluids to facilitate penis entering vagina









TSEVSPB
testis - generate sperm
scrotal sac - houses testes, regulates temperature
epididymis - where sperm gain mobility
vas deferens - sperm transportation
seminal vesicles - adds fructose to sperm, energy for sperm , prostaglandsins whcih cause smooth muskcles in femal reproductive tract to contract
prostate gland - stimulate sperm to move, neutralize acidic fluids of female reproductive tract
bulbourethral gland - produces lubricating fluids to facilitate penis enterign vaigna
TSEVSPB
testes - generates sperm
scrotal sac - houses sperm , temperature regulation
epididymis - where sperm gain mobility
vas deferens - sperm transportation
seminal vesicles - add fructose to sperm, energy forspem, prostaglandins which cause smooth muscl of female reproductive tract to contract
prostate gland - neutralize acidic fluids in female reproductive tract, stimulate sperm to move
bulbourethral gland - produces lubricating fluids to facilitate penis entering vagina

female reproductive system - 28 day cycle
day 0-5 - menstruation - inner lining of the uterus sloughs off, lost its hormonal support and dies and sloughs off, the blood vessels that have grown into it are broken
day 0-14 - follicular phase - follicle is mature
day 14 - ovulation - estrogen levesl spike, bigger spike in hormon LH - luteinizing hormone - causes follicle to rupture and for the egg to be released
14-28 - luteal phase - corpus luteium - yellow body - follicul becomes the corpus luteum - secretes progesterone, as corpus luteum develops, progesterone levesl increase
progesterone - incerase the vascularization of th eendometrium (inner lining of the uterus)
24-28 - if egg has not been fertilized , the corpus luteum breaks down, progesterone levels plummet, eventually endometrium loses hormonal support and will slough off....

2 uteri (fallopian tubes) - have all the eggs in tehm ,lead to uterus
cervis - opening to the uterus
vagina - birth canal

meiosis - HALVES the number of chromosomes
a diploid cell (2n) has a full set of genetic info carried on paired chromosomes called homologouis pairs. homologs have the same genes in the same order but may have different alleles. meiosis produces 1n haploid gametes. somatic cells are diploid, mature cells are haploid.....
what would happen if meiosis did not occur in reproductive cells - we would have double the number of chromosomes
polyloid - too many chromosomes
meiosis results in a mixing of comibinations of traits. no two individual gametes are genetically identitcal. the result is genotypic diversity.
prophase I
synapsis - homologs line up next to each other gene for gene
homologs exchange pieces of themselves - creates more genetic diversity
crossing over occurs
metaphase I - homologs separate. which chromosome goes to which pole is completely random - independent assortment - creates more genetic diversity
mitosis
1 division , no crossing over, in the first division, sisters separate, daughter cells are diploid, daughter cells are identical
meiosis
2 divisions, crossing over, in the first division, homologues separate, daughter cells are haploid . daughter cells are different

spermatogenesis (sperm production)
beings woith males at puberty, begins in a diplod cell called a spermatogonium - divides y mitosis yielding 2 daughter cells, yields 46 chromosomes, one of these cells becomes a sperm cell (primary spermatocyte) the other remains an undifferentiated stem cell. primary spermatocyte then undergoes meiosis and produces 4 spermatids, stem cell becomes a spermatogonium and divides by mitosis. as a result males can produce reproductive cells all their live....telomerase gets produced so that this process can continue indefinitely

spermatozoa (sperm)
have 3 separate regions
head - acrosome - contains powerful hydrolytic enxymes, allows sperm to get to oocyte. nucleus - haploid, holds DNA of the sperm
midl=piece - mitochondria - produce energy to get the flagellum to work
tail( flagellum) - allows sperm to move
egg - surrounded by a thick layer of protective mucus that sperm cells cannot penetrate without help. when a sperm reaches the impenetrable barrier, the acrosome bursts open, digesting a pathway for the sperm cell to get to the egg

oogenesis - oogonium - divides by meiosis but does not divide equally , one of the cells gets organelles, cytoplasm, everything it needs to survive called an oocyte
polar body undergoes a meiotic division to make 2 more polar bodies
oocyte undergoes a meiotic division to make another oocyte and a polar body

embryo - first 8 weeks
fetus - 9 weeks to birth
fertilization
sperm can survive in the female reproductive tract for up to six days. most however only last about 48 hours. cthe oocyte has a very narro windo of oppotunity for fertilization - 12 to 24 hours after ovulation
sperm are aided in their 7 inch journey by
prstaglandins - were added byseminal vesicles - cause contractions of the muscles in female reproductive system which help push the sperm cells along
capacitation - release of chemicals by the feamlae's reproductive tract that activeate the sperm- sperm activated
cilia create a current of mucus
oocyte releases sperm-attracting chemicals
acrosome bursts when sperm cell comes in contact with the protective layer around the oocyte forming a tunnel through the layer of glycoprotein
early cells - BLASTOMERES - formed from the cleavage of ovum
when blastomeres form a solid ball of 16+ cells,the embryo is called a MORULA
ball of cells beings to hollow out and center beomces filled with FLUID called BLASTOCYST

supportive structures
chorinoic villi - fingerlike projections from th embryonic disc that dip into pools of the mother' s blood. mom and babies circulatory systems are separate, but nutrients and oxygen diffuse across the chorionic villi from her circulatory to embryos circulatory system. waste leaves the embryo and enter mome's circulation for excretion
placenta - fullly formed after 10 weeks. the placenta produces hormones that suppport pregnancy and alter the woman's metabolism to bring nutrients to the fetus
yolk sac and allantois - yolk sac - manufacture blood allantois - helps embryo exchange gases and handle liquid waste
rates of DZ twins vary with different populations
MZ twin rates have nothing to dowith mom's age, health, or other MZ twins in a family
sex is dteremined at conception - SRY gene on Y chromosome "turns on" maleness
1st trimester - fetus kicks, makes faces, sucks its thumb....breahtes amniotic fluid to exercise the lungs, urinates, and poops
2nd trimerster
month 4 - getus has hair, nails, lashes, nipples...vocab cords develop
month 5 - fetus curs in head to knee position and weights about a pound
month 6 - fetus appears to have wrinkled sking because there is little fat underneath. by end of 2nd trimester, mom can detect hiccups, fells definite kicks, jabs, fetus is about 9 inches long
3rd trimester
brain is very actively developing networks. organs are growing. subcutaneous fat layer develops. digestive and respiratory systems are last to develop.
birth defects - caused by genetic abnormalities, toxic substances, viruses
critical period - time when a particular developing structure is vulnerable
teratogens - chemicals or other agents that cause birth defects
thalidomide - morning sickness drugs forpeople early in pregnancy when limbs are