Bio-biochem Flashcards
cell theory our basic tenets
all living things are composed of cells
the cell is the basic functional unit of life
cells arise only from preexisting cells
cells carry genetic information in the form of DNA and it is passed on from parent to daughter cell
eukaryotic cells characteristics
nueclus enclosed inside a membrane and unicellular or multicellular
prokaryotic cells char
do not contain a nucleus, always single cells
importance of membrane bound organelles
compartmentalization of function
membranes are made up of a
phospholipid bilayer. Inside is hydrophilic (likes water) and outside is hydrophobic (hates water– selective barrier)
cytosol
allows for diffusion of molecules throughout the cell
nucleus
genetic material is encoded in DNA which is organized into chromosonmes and kept in nuc
control center of the cell
nucleus is surrounded by:
nuclear membrane or envelope, a double membrane that maintains a nuclear environment separate and distinct rom the cytoplasm
nuclear pores
in the nuclear membrane which allows selective 2 way exchange of material between nucleus and cytoplasm
linear DNA is wrapped around
histones
histones are wrapped together to form
chromosomes
nucelolus
subsection of the nucleus where rRNA is synthesized.
mitochondria layers
outer and inner membrane
outer memrbane
barrier between the cytosol and the inner environment of the mito `
cristae
inner foldings of the inner membrane of the mito
increase surface area for electronic transport chain electrons
space between inner and outer mito membranes
inter membrane space
space aside the inner membrane
matrix
mitochondria purpose
involved with ATP production and apoptosis
nucleus purpose
stores genetic information and is the site of transcription
lysosomes
break down cellular waste products and molecules ingested by endocytosis- also involved with apop
has hydrolytic enzymes that break down substances
RER
synthesizes proteins destined for secretion
continuous from the nuclear envelope
studded with ribosomes (translates proteins)
SER
involved with lipid synthesis and detoxification
GOLGI
packages, modifies (addition of groups like carb, phosphates, sulfates or introduce signal sequences) and distributes cellular processes
stacked membrane sacs
ER to Golgi via vesicles
peroxisomes
break down very long chain fatty acids (via beta oxidation), synthesis lipids and contribute to the pentose phosphate pathway
contain hydrogen peroxide
extranuclear inherientence
mito does this- the transmission of genetic material independent of the nucleus
endosomes
work with lysosomes in transporting, packages and sorting cell material from the membrane
cytoskelton
structure to cell and helps maintain its shape
components of cytoskelton
microfilaments, microtubules and intermediate filaments
microfilaments
composed of actin.
compression and fracture resistant, protect cells
interact with myosin and ATP to move in muscle contraction
play a role in cytokinesis (division of material between daughter cells– pinching off in ring)
microtubules
composed of tubular
hollow
motor proteins like kinesis and dynnein carry vesicles
examples of tubules are cilia and flagella
intermediate filaments are composed of
depends on cell type- either keratin, design, vimentin and lamins
involved with cell to cell adhesion or maintenance of overall integrity
tension held, increase rigidity of the cell
help anchor nucleus to membrane
centrioles consist of
nine triplets of microtubules around a hollow center
flagella consists of
nine doublets on the outside, with two microtubules on the inside
epithelial cell types
endothelial cells and alpha cells
connective tissue cells (basement membrane)
fibroblasts, osteoblasts, chondroblasts
provide support and framework for epithelial cells
cilia and flagella both have the same structure
9 +2: nine pairs of microtubuleson outside and 2 microtubules in center
centrioles
organizing centers of the microtubules— they are the hollow center
in mitosis
microtubules expand from centrioles attached to chromosome via kinetochores and spread sister chromatids apart
epithelial cells purpose
protection against pathogen invasion and desiccation, line the body
involved in absorption, recreation an sensation
tightly together and bind with basement membrane
parenchyma
the functional parts of an organ are made up of epithelial cells, like the nephrons in the kidney
simple epithelia have
1 layer of cells
strafed epiehtlia have
many layers
psyedostratified epihetlic
appear to have many layers due to their differences in heights, but rlly 1 layer
connective tissue contribute to
stroma or support structure
bone, cartildge, tendons, ligaments, adipose tissue and blood
form extracellular matrix through secreting collagen and elastin
prokayrotes have circular DNA located in the
nucleoid region
archea and bacteria both contain
prokayarotes
archae
single celled organisms that are similar to bacteria, but contain genes and many metabolite pathways more similar to eukaryotes
harsh environments
alternative sources of energy- photosynthetic, chemosynthetic, etc.
eukaryote and archaea both share
MET as translation, contain similar RNA polymerases and have DNA with histones
all bacteria contain
cell membrane and cytoplasm, and some have flagella or fimbriae
bacteria shapes
cocci (spheres), bacilli (tubes), and spirlli (looks like twisted rope)
obligate aerobes
bacteria that need O2 for survival
anaerobes
no o2, use fermentation
cannot survive in O2 setting- obligate anaerobes
obligate anaerobes
cannot survive in O2 setting- create radicals
facultative anaerobes
use o2 when present then switch to anaerobic mechanisms if necessary
aerotolerant anaerobes
unable to use oxygen for metabolism bu are not harmed by it
prok lack
nucleus and membrane bound organelles
single celled! they are!
cell envelope
cell wall and cell membrane together
cell wall
provides structure and controls the movement of solutes into and out of the bacterium
types of cell wall
gram positive (absorbs violet stain) and gram negative (does not absorb stain, bu does safranin and appears pink)
gram positive walls
contain peptidoglycan, a polymeric stance made om amino acids and sugars.protection and immunity
also contains lipotecichoic acid
gram negative walls
rlly thin and also contain peptidoglycan, but in smaller amounts.
have outer membrane with phospholipids and lipopolysaccharides (immune response much bigger than in positive walls)
flagella
whip like projections to move away from toxins or to food
chemotaxis
ability of cell to move to or away from chemical stiujmli and detect it
bacterial flagella vs. eukaryote flagella
eukaryote contain microtubules composed of tubulin, in. a9+2 arrangement, bacterial flagella are made of flagellin and consist of filament, basal body and hook
binary fission
asexual reproduction seen in prokaryotes - circa;ar chromsomes attaches to wall and replicates while cell grows in size and then cell wall and membrane grow inward and split aMong midlien
2 identical daughter cells
plasmids
extrachromosomal material in bacteria
carry antibiotic resistance
some benefit, like toxins or virulence factors (increase pathogencitiy)
episomes
type of plasmid that integrates not genome of bacteria
bacteria genetic recombination purpose and steps
increase bacterial diversity and permit evolution
transformation, conjugation and trasduction
transformation
integration of foreign genetic material into the host genome
mostly from bacteria that upon lysing, spill their contents into other bacterium
conjugation
bacteria form of mating- sexual reproduction
2 cells that form a conjugation bridge and transfer genetic material between them – unidirectional (donor male to recipient female). Bridge made from sex pili from the male (F factor + and if dont have it they are F-). The sex factor is a plasmid, but through transformation cab be integrated into host genome (deemed Hfr)
transduction
contains a vector- a virus that carries genetic material from 1 bacterium to another. cannot reproduce outside of hist cell, so bacteriophages can be incorporated into DNA in assembly. then it can release its trapped DNA into new host ell and integrate it for more genes.
transposons
genetic elements capable of inserting and removing themelsves from the genome. prok and eukaryote.
bacteria growth
lag phase- adapt to new environment
exponential phase or log phase- division increases, increase in number of bacteria in colonu
stationary phase- reduction in resources due to this reproduction, and therefore it slows down
death phase- after bacteria have exceeded the ability of the environment to support them
viruses are composed of
genetic material, protein coat (capsid), sometimes an envelope containing lipids (easy to kill because sensitive)
genetic material can be circular or linear, single or double, composed of either DNA or RNA
because viruses cannot reproduce independently they are considered
obligate intracellular parasites. must express and replicate genetic information in. host cell because they lack ribosomes to carry out protein synthesis.
viral prodigy
virions
bacteriophages
viruses that target bacteria. inject genetic material, dont enter. tail sheath acts as a syringe and tail fibers help connect virus to bacteria
positive sense
genome may be directly translated to functional proteins by the ribosomes of the host cell, just like mRNA
single stranded RNA viruses can be
positive or negative sense
negative sense
Rna viruses are complex- negative sense RNA acts as a template for synthesis of complementary stand, which Is used for a template for protein synthesis
carry RNA replies in the virion to ensure complementary strand is being synthesized.
retoviruses
enveloped, single stranded RNA viruses- virion contains 2 RNA mc.
carry reverse transcriptase, which syntheses DNA from single stranded RNA and DNA integrated into host cell and replicated as if host’s own DNA.
HIV
only way to remove infection is to kill the cell.
prions
cause diseases by triggering misfolding of other proteins, usually from converting them from an alpha helix structure to a b pleated sheet. cell cannot degrade and insolubility. aggregates for,.
viroids
very short circular single stranded RNA that infect plants
lytic cycle
bacteriophages replicate in the host cell in high numbers until hose cell lyses and releases virions.
lysogenic cycle
bacteriophage enters the host genome and replicates with the host cell as provirus. provirus can leave host genome and used to synthesize new virions.
diploid
2n- two copies of each chromosome. autosomal cells are diploid. 46 in humans
haploid cells
germ cells. (n)- containing on only one copy of each chromosome. 23 in humans (from each parent we inherit 23)
cell cycle
a specific series of phases during which a cell grows, synthesizes DNA and divides. Derangements can lead to unchecked cell division and cancer. Stages are G1, S, G2 and M
interphase
G1, S and G2. Longest part of the cell cycle. Chromsones are in less condensed form and called chromatin, so that genes are available for RNA poly to be transcribed. During mitosis, DNA is tightly condensed to chromosomes to avoid losing any genetic material during cell division.
cells that do not divide spend all their time in an offshoot of G1, called G0
cell is simply living and carrying out its functions without any prep for division.
G1 stage
cells create organelles for energy and protein production (mito, ri, ER), while also increasing size. In order to get into S phase, go through restriction point, which checks if the cell has the proper complement of DNA (DNA good enough for synthesis). If not good enough, then cel goes into arrest until RNA repaired- main protein is p53
S stage
cell replicates its genetic material so that each daughter cel will have identical copies. after, each chromosome consists of two identical chromatids that are bound together by a centromere. Still 46 chromosomes.
G2 stage
cell passes through another quality control checkpoint. DNA is duplicated and cell checks to ensure enough organelles and cyto for 2 daughter cells. Also checks for error in DNA replication. p53 plays role here.
M Stage
Mitoriss and cytokinesis. Mit is divided into 4 stages-prophase, metaphase, anaphase and telophase. Cytokinesis is the splitting of the cyto and organelles bw the two daughter cells. Somatic cells- cells not for sexual reproduction.
molecules responsible for cell cycle
cyclins and cyclins-dependent kinases (CDK). CDK activated with cyclins present and phosphorylate TF (transcribe genes required for next stages). Binding fluctuates in cell cycle.
cancer
when cell cycle control becomes deranged and damaged cells under mitosis, cancer happens. mutations in cancer are with p53 production gene, TP53. when mutated, cell is not stopped to repair damaged DNA and mutations accumulate and cell divides cont- creating tumors. can start to reach other tissues and invade in blood stream or lymphatic system- metastasis
prophase
condensation of the chromatin into chromosomes. centriole pairs separate and more toward opposite poles of the cell. these paired organelles are located in the centrosomes. Centrioles migrate to ends of cells and form spindle fibers, made of microtubules.nuclear membrane dissolves during prophase and these spindle fibers connect to chromosomes . nucleoii dispeappar. kinetochores- attachment points for fibers of the spindle on the centrosome.
metaphase
centriole pairs are now at opposite ends, kinetochores align chromosomes at meta plate (equatorial plate, between two poles
anaphase
centromeres spoilt so that each chromatid has its own distinct centromere, sister chromatids seperate, shortening kinetochores pull to opposite poles
telophase
reverse of prophase. spindle apparatus gone. nuclear membrane reforms around chromosomes and nucleoli appears. chromosomes uncoil with interphase form. each of the two new nuclei receive a copy of the genome identical to the original genome and to each other
cytokinesis
end of telophase, separation of the cytoplasm and organelles, giving each daughter cell enough material to survive on its own.
meiosis
occurs in gametocytes (germ cells) and results in 4 nonidentical sex cells (gametes).
meiosis and mitosis similarities
genetic material duplicated, chromatin condensed to form chromosomes and microtubules emanating from centrioles are involved in dividing genetic material.
differences in meiosis compared to mitosis
mitosis- 1 round of replication and divsion
meoissi- one round of replication, 2 rounds of division
meiosis 1
homologous chrome being separated, creating haploid daughter cells– reductional division
meiosis 2
similar to mitosis- results in separation of sister chromatids with a change in ploy - equational division.
human genome has
23 homologous pairs of chromsomes (homologues), eacch contain 1 chromosomes from each parent. after s phase, there are 92 chromatids, 46 chromosomes and 23 homo pairs
meiosis prophase 1
same as mitosis except homologous chromosomes come tg and intertwine with synapsis. So each chromosome has 2 sister chromatids and 4 chromatids in a synaptic pair – tetrad.
chiasma
sister chromatids of the homologue chrome break at chiasma and exchange DNA in crossing over (single or double)
crossing over occurs in prophase 1 of
homologue chromosomes , not sister chromatids of same chromosome.
recombination
increasing variety of genetic combinations that can produced via gametogenesis.
linkage
tendency for genes to be inherited togehter- father away= not likely
because of crossing over
each daughter cell will have a unique pool of alleles. from a random mixture of paternal and material orign
metaphase 1
homologous pairs (tetrads) align on plate and each pair attaches to ONE (not 2 like mitosis) spindle fiber by kinetochore.
anaphase 1
each homologue pair operate- called disjunction. random with what chromosomes end up in either daughter cell.. segregation.
telophase 1
nuclear membrane reforms. each chromosome has 2 sister chromatids joined at centromere. cells are haploid (n- 23 chromasomes). cell divides into 2 daughter cells by cytokinesis and there may be interkinesis, chromosomes partially uncoil
meiosis 2
similar to mitosis- sister chromatids.
biological sex is determined by
the 23rd chromosomes
Ova carry the
x chrom
X chrom
can cause sex (x) linked disorders- carry most genetic info
males are termed
hemizygous . recessively inherited so F express much less than males (if males have it, they show it, cant hide it or be carriers like females)
Y Chrom SRY gene
sex determining region Y- codes for transcription factor that imitates tetis differentiation and male gonads. So without Y chromosomes, female.
testes:
seminiferous tubules and intersitutal cells of Leydig. Sperm is produced in seminiferous tubes and nourished by Sertoli cells. Cells of leydig secrete testeerone and other m sex H (androgens)
testes are located in the
scrotum. as sperm form, they pass through the epididymis and stored until ejculation. travel through vas deferent and enter ejaculatory duct in prostate gland.
spermatogensis
formation of haploid sperm through meiosis, occurs in semi tubes. diploid cells are known as spermatogonia.
production of female gamates
oogensies . all oogonia formed during detal development
primary oocyte
arrested in prophase 1/ at birth.
asecondary oocyte
arrested in metaphase 2. at first period. and polar body
acrosome
contains enzymes that are capable of penetrating the corona radiate and zone pellucid of the ovum, permitting fertilization to occur ,modified by Golgi.
androgens, like testetrone, lead to male sex differentiation. absence of androgens receptors is known as
andoren insentisitvity syndrome, leads to XY genotype with phenotypically female char
follicular
high FSH, high LH, drop then high estrogen and down progesterone. egg develop,s endometrial lining becomes vascular and glandular. regrowth
ovulation
egg is release from follicle int pweironeal cavity. high FSH and LH and Estrogen. down progesterone. high lH leads to ovulation, release of ovum from the ovary.
Luteal
corpus leutum produces progrestrone to maintain endometrium. low FSH, = LH, high estrogen and progesterone. prevent ovulation of too many eggs.
menses
shedding of endometrial living. down all H
FSH stimulates Sertoli cells and triggers sperm maturation as LH causes
intersisytal cells to produce T
estrogen is secreted in response to FSH
leads to thickinign of endometrium and secondary char.
progesterone
secreted by the corpus letueum in response to LH. involved with deveopmetn and maintenance of endometrium.
menstrual cycle
follicular phase, ovulation, luteal and menses
pregnancy
hCG will be secreted- keeps lining in place by nurturing corpus leutum which keeps progrestrone and estrogen working. placenta takes over hCG ‘s job
menopause
ovaries less sensitize to FSH and LH, ovarian atrophy. drop in progresterone and estrogen lead to endometrium down leads to no period.
amino acids
contain an amino group (NH2) and a carboxyl group (COOH). alpha carbon is where these groups attach to , the carboxylic acid carbon, central carbon.Also has a H and a side chain (R Group) attached to the central C. R group is specific to each amino acid
alpha C
chiral/stereogenic center, as it has 4 diff groups attached to it. most amino acids are optimally active. Exception is glycine, which has H as an R group and makes it achiral. All amino acids (but cystin) are L-amino acids and S confirguartion.
amino acids with polar, nonromantic side chains
glycine (small), alanine, valine, leucine, isoleucine, methionine, proline
amino acids with aromatic side chains
tryptophan, phenylamnine, tyrosine
amino acids with polar side chains
serine, threonine, asparagine, glutamine, cysteine
amino acid with negatively charged side chains
aspartic acid, glutamic acid
amino acids with positively charged side chains
ariginine, lysine, histidine
hydrophobic
all AA with long alkyl side chains (alanine, leucine, isoleucine, valine and phenyalanine)— founds interior of proteins away from water
hydrophilic
all aa with charged side chains- + charged histidine, arginine, lysine and - charged glutamate and aspartate as well as aspatartic and glutamic acid
Abbreivations
Alanine- Ala- A Arigine- Arg- R Aparagine- Asn- N aspartic acid- asp- d cystiene-cys- c GLUTAMIC acid- glut-E Glutamine- Gln- Q glycine- Gly-G histidine- His- H isoleucine- Ile- I Leucine- Leu- L lysine- Lys- K metthionine- met- M phenylalanine- phe- f proline-pro-P serine- ser-S threonine- thr- T tryptophan- trp- W Tyrosine- Tyr-Y Valine-Val-V
amino acids, with both acidic carboxylic group and basic amino acid group
makes them amphoteric species- either accept a proton or donate a proton depending on the pH of the environment.
ionnzable groups tend to
gain protons under acidic coniditions and lose them in basic conditions.
at low pH= protonated
at high pH= deprotonated
the pKa of a group is the PH
at which half of the mc of that species are deprotonated
if pH is less than pKA = protonated
if PH is more than PKA= deproontated
amino acids have two pKa
pKa for carboxylic acid= 2
pKa= amino group= 9-10
ionizable side chains- have 3 pKa
at very acidic but above 2 value
pH will be +
zwitterions
7.5. Amino group is protonated so +, COOH- group is above so deporontated and -.
pI
isoelectric point- the Ph at which the mc Is electrically neutral
pI= PKA NH3 + group + pKA COOH group/2
peptides
amino acid subunits (residues)
dipeptides- 2 AA residues
tripeptides- 3
oligopeptide- small peptides up to about 20 residues while longer chains are called polypeptides
residues joined together via peptide bond– between -COO- soup of one aa and the NH3+ group of another aa
peptide bond formation
dehhydration or condensation reCTION BECUSE IT RESULTS IN THE REMOVAL OF WATER
electrophilic carbonyl carbon on the first a is attacked by nucleus amino group on second aa.
enzymes break apart of proteins by
breaking apart the amide bond by adding hydrogen atom to the amide nitrogen and an Oh group to the carbonyl carbon
primary protein level
linear barrage,net of amino acids in DNA. peptide bond
secondary
`hydrogen bonding between neighboring amino acids- alpha helixes and beta pleated sheets. hydrogen bonds
proline- kink in the peptide chain when found in the middle of an alpha helix
rarely found therefore, unlesss cell membrane. creates turns in beta sheets.
alpha helix is a rod like structure in which the peptide chain
coils clockwise around the central axis. b sheets the peptide chains lie alongside one another, rows together by hydrogen bonds
tertiary structure
3D shape of protein, hydrophobic interactions, acid-base salt bridges, disulfide links– bonds are LDF, H, optic and covalnt
quart structures
interaction between separate submits of a multisubunit protein, same bonds as quart.
moving Hydrophobic resides to the interior of a protein
increases entropy by allowing water molecules on the surface of the protein to have more possible conjurations .positive delta S makes delta G negative stabilizing proteins
prosthetic groups
lipids, carbs, NA— lipoproteins glycoproteins and nucleoproteins
direct protein and determine function
example is HEME group
denaturation
in which a protein does its 3D- heat and soluytes
higher heat =
unfolding
solutes
disrupt quart and tertiary structure by breaking disulfide bonds. reducing Cysteinem and breaks apart secondary structures
catalysts
enzymes- do not imp the thermodynamics of a biological reaction, delta H and equilibrium position do not change. . Increase reaction rate by lowering activation energy, increasing rate of reaction, not changed or consumed int eh reaction, are pH and temp sensitize, do not effect overall delta G and scenic for a particular reaction or class of reactions
enzyme specificty
a given enzyme will only catalyze a single reaction or class of reactions, with these usbtrates
oxidoreductases
catalyze oxidation- reduction raccoons- the transfer of electrons between molecules. Have electrons carriers like NADP+. Donor is known as reductant and electron acceptor is oxidant.
LIL HOT
ligase, isomerase, lyse, hydrolase, oxidoreductase, transferase
transferase
catalyze the movement of a functional group from one molecule to another. ex. moving an amino group. Kinases included, which transfer a phosphate group, from ATP, to another mc
hydrolases
catalyze the breaking of a compound into 2 mc using addition of water/- phosphates, peptidases, lipases etc
lyases
catalyze the clear of a single molecule into 2 products. not require water.
isomerases
catalyze the rearrangement of bonds within a molecule.
stereoisomers and constitutional isomers
ligases
catalyze addition or synthesis reactions, generally between large similar molecules and require ATP often. NA synthesis mostly
enzyme affects thermodynamics by:
energy states of the reaction.
enzyme affects kineticss by:
rate of reaction, how quickly a reaction gets to equilibrium but not the actual equilibrium state itself is touched.
lock and key theory vs. induced fit model
in lock and key it assumes active site (lock) is already in appropriate conformation for key to bind as in indices it, enzyme is a foam stress ball and substrate is a hand, they conform together.
cofactors
inorganic molecules or metal ions, ingested as dietary minerals, enzymes require these nonprotein molecules to be effective in catalysis
coenzymes
small organic groups, vitamins like NAD+, coenzyme A and DAS
{s}
concentration of the substrate –starts off increasing rlly high and then levels off as less enzyme becomes available with increasing substrate
Michalis-Menten equation
describes how the rate of thr reaction, v, depends on the convention of both the enzyme {E} and the substrate [s] which form [p]. enzyme substrate completes form at a rate Ki. The ES complex can either dissociate at a rate k-1 or E +P at rate K cat
v= vmax ([s])/ Km + [s]
Km= [s]
plot- v vs. [s], creating hyperbolic curve
Michaelis constant
Km- substrate concentration at which had of the enzymes active sites are full. measure of enzymes affinity for a substrate. as km increases, an enzymes affinity for a substrate decreases
when. substrate concentration is slo
an increase in [s] causes increase in enzyme activity. at high [s], enzyme is saturated and no effect on activity cause max is met
increasing [e] will always increase
max, regardless of starting concentration of enzyme
line weaver-burk plot
1/v vs. 1/[s], creating a straight line. same as mention plot
line weaver-burk plot x and y
x= -1/km, y = 1/vmax
enzyme cooperativty
interactions between subunits in a mulitsuunut enzyme or protein. the binding of substrate to one subunit induces a change in other subunits from the T (tense) state to the R (relaxed) state, which encourages binding of substate to others. in unbinding, R to T,
as temperature increases, enzyme activity generally increasing.
above body temp, enzyme cavity drops off as enzyme denatures. enzymes are max active within a small pH range, denatured if not. changes I salinity can disrupt bonds within an enzyme, causing distruption of tertiary and quart structures, lose of function
ideal temp for enzymes
37 degrees C= 310 K= 98.6 F
ideal pH for most enzymes is
7.4. for gastric enzymes: 2, pancreatic enzymes: 8.5
feedback inhibition
product of an enzymatic pathway turning off enzymes further bacteria kin that same pathway. maintain homeostasis as a product level rise, the pathway creating the product is downregulated
increases km
competetive inhibitor- sub concentration has to be higher to reach the max velocity in th presence of the inhibitor. a mixed inhibitor will increase km only if inhibitor partially binds to the enzyme over the enzyme substreate complex
irreversible inhibition
prolonged, permeant inactivation of an enzyme, cannot be renatured to gain function
transient modificationa- activated or deactivated enzymes
allosteric or inhibition
covalent modifcations- activated or deactivated enzymes
phosphorylation and glucosulation
zymogens are precursors of
active enzymes. critical for certain enzymes (digestive enzymes in the pancreas) remain inactive until arriving at target site.
neurons
specialized cells capable of transmitting electrical impulses and then translating those imputes into chemical signals.
neuron nuc is located in the
cell body, or soma
dendrites
received incoming messages from other neurons
axon hillocks
integrate the neuron signal- plays a role in AP, which transmit electrical impulses down a axon. Excitotry or inhibitory sugnals
axon
long appenadage that terminates in close proximity to a target structure
myelin
insulation of fat to prevent signal loss or crossing of signals. also increases speed and maintain electrical signals within 1 neuron. produced by oligodendrocytes in CNS and Schwann cells in PNS
nodes of ranvier
small breaks in myelin sheath exposed axon membrane-critical for rapid signal conduction
nerve teerminal
max transmission of the signal to next neuron and release NT
nerve terminal, synpaticcleft and post synaptic membrane are known as
the synapse
multiple neurons may be bundled together t form a nerve
in the PNS- sensory, motor or mixed
collection of cell bodies at CNS is
nucleus
collection of cell bodies at PNS is
ganglion
astrocytes
nourish neurons and form BBB, which control transmission of solutes from bloodstream to tissues in nervous system
ependymal cells
Line the ventricles of the brain and produce cerebrospinal fluid, which support the brain and serves as shock absorber
microglia
phagocyte cells that ingest and break down wast products and pathogens in the CNS
olgiodenrocytes (CNS) and Schwaan cells (PNS)
produce myeline around axons
cells resting membrane potential
net electric potential difference that exists across cell membrane, created by movement of charged mc across membrane. -70 mV, inside more negative than outside
potassium is more
inside than outside - wants to move out. has potassium leak channels, slowly leak out and create neg inside and pos outside. however negative charge inside the cell attratcs pot to stay. electrical current vs. chemical gradient- equals! 1:1- so equilibrium potential of pot
around -90 mV
sodium is more
inside than outside- push to rush inside- sodium leak cahnelles. electrical potential pulls sodium back into cell. _60 mV
resting membrane poteital
between pot and sod- -70 mV
NA/K ATPASE
pump sodium and pot back to where they started- done by ATP
exhibitory input causes
depolarization- raising membrane potential frmresting and neuron more likely to fire
inhibitory input causes
lowering Mem poetical from its resting- hyperpolizartion and neuron less likely to fire AP
threshold value
-55 mV to -40 mV
many signals to a post from many pre synaptic
summation
types of summation
temoporal and spatial
temporal summation
many signals are integrated during short period of time. small excretory signals firing at some moment can bring cell to threshold
spatial summation
additive effects are based on number and location of signals- a large number of inhibitory signals firing directly on soma will cause a more profound hyperpolization of the axon hillock then the depolarization caused by a few excretory signals firing on the dendrites
AP
if cell is brought to threshold, voltage gated ion sodium channels open in the membrane in response to the change in potential (depol) and permit the passage of sodium ions - strong electrochemical gradient that promotes the migration of sodium into the cell. as well as gradient concentration because more out than in- so NA Rushes in. when Vm approaches +35, sodium channels are inactivated. This makes pot voltage gated channels to open and drive outside the cell through replorization. – makes th neuron refractory to further AP
absolute refractory period
no amount of stimulation can cause anther AP
relative refractory period
there must be a greater than normal stimulation to cause an AP because starting at even farther negtaive value I
IMPULSE propoganda
for a signal to be conveyed to another neuron, AP use travel down axon and imitate NT release- increased length of axon results in higher resistance and slower conduction. cross sectional allows for faster progofanda due to decreased resistance
salutary conduction
signal hops from node to node, nodes of ran view because myelin maximizes speed of transmission
Nt
stored in membrane bound vesicles in nerve terminal. when AP reaches, Ca channels open and allow Ca to flow into the cell ad trigger vesicles to let go of NT
ligand gated ion channel
deplorized or hyperpolizard
GPCR
change sin levels of cAMP or influx of Ca
removing NT
by enzymatic reactions, reupake carriers, diffuse out of synapse.
sensory neurons
afferent neurons - sensory receptors to brain and spine
motor neurons
efferent- transmit motor info from brain to msucels
interneurons
most numerous. Brin and spinal cord and reflex
brain white mater
axons with myeline sheath
grey matter brain
unmyelinate cell bodies and dendrites
spinal cord
cervical, thoracic, lumbar, sacral
cell bodies of sensory neurons in
dorsal root ganglia
PNS connects CNS
to rest of bodylm
somatic system
sensory and motor neurons throughout skin, joints and muscles.
ANS
heartbeat, respiration, digestion, secretions- involtunary. , body temp
relfex arcs
controls reflexive behavior- internerons in spinal cord send out signals instead of waiting for the brain to do it
monosyantpic reflex arc
there isa single synapse between the sensory neurons that receives the stimulus and the motor neuron that responds to it- knee jerk reflex
polysnaptic reflex arc
at least 1 internerons between the sensory and Motor neurons- withdrawal effect when stepping on a nail– mono in which u will flex the hurt foot and pull away, bt to maintain balance, have to control other leg too
glands
secrete hormones
hormones
signalling molecules secreted directly into the bloodstream to distant target tissue. Bind to a receptor and cause a change in gene expression or cell function
hormones classified by chemical identifies
peptides, steroids, amino acid derivatives
peptides H
made up of aa, ranging from small to large (ADH to insulin). They are charged and cannot pass through the pm - bind to exxtraceullar receptor. Peptide H is considered first messenger, and triggers the transmission a second messenger – signaling cascade and ampliciation and signal intensity (activate many enzymes)
second messeners
cAMP and IP3 and Ca2+
peptide hormones are
rapid and short lived bc act through second messenger cascades- wicker to turn them off and on compared with steroid hormones
peptide H are water soluble and can travel freely in bloodstream and dont need carrier.
steroid hormones
lipid soluble.
derived from cholesterol- produced by gonads and adrenal cortex. Easily cross cell membrane because non polar. Receptors are therefore intracellular (in cytosol) or intranueuclar (in nucleus). Binding can cause conformational changes, like binding to DNA and result in increased or decreased transcription of genes.
conformational change can be dimerization, pairing of 2 receptors hormone complexes
slower and long lived- alter mRNA and protein present by direct action on DNA
steroid hormones are not
water soluble and need to be carried by proteins in the bloodstream - proteins can be specific and carry any 1, or general and many. must disscoiate from protein for H to function. levels of carrier proteins change the levels of active hormones
amino acid derivative H
epi, nor, triiodothyronine, thyroxine - derived from 1 or 2 amino acids and modification
catecholines (epi and nor) bind to GPCR and thyroid H bind intracellularly
direct H
secrets and direct bind onto a target tissye
insulin causes increased uptake of glucose by muscles
tropic hormones
rehire an intermediate to act
GnRH from hypothalamus stimulate the release of LH and FSH . LH acts on gonasd and stimulate testetrone
peptide and aa derivative H have names that end with -in
insulin, vasopressin, throne. many steroid hormones have names that end with -one, -ol, -oid (cortisol, testestrnoe)
endocrine glands
hypothalamus, pituitary, thyroid, parathyroid, adrenal, pancreas, gonads, pineal gland
hypothalmuns
bridge between nervous and endocrine systems
regulates pit gland with tropic H.
in forebrain- above pt gland and below thalamus
controls pit gland by release of H into portal system
negative feedback
when a hormone later int eh pathway inhibits hormones earlier in the pathway
maintains homeeostatsis and conserves energy
the hypothalamus secretes compounds into the
hypophyseal portal system which is a blood vessel system that directs connects the hypothalamus with the anterior pit
hypothalamus secretes many tropic H
GnRh, RHRH, TRH, CRF
GnRH
gonadotropin-releasing H from hypothalamus– stimulate release of follicle stimulating H (FSH) and luteinizing hormone (LH) from anterior pit. target gonads (testes and ovaries) which release Testosterone and estrogen and progesterone
GHRH
growth hormone releasing hormone from hypothalamus,us stimulates release of GH (growth hormone) from anterior pit
bind to bone muscle
TRH
thyroid releasing hormone from hypothalamus and stimulates release of thyroid stimulating H (TSH) from anterior pit
targets the thyroid and released triiodothyronine and thyroxine
CRF
corticotropin releasing factor from hypothalamus stimulate release of ACTH (adrenocorticotropic hormone) from anterior pit
taget adrenal cortex and release glucocorticoids (cortisol and cortisone )
hypothalamus –> CRG –> ant pit –> ACTH –>adrenal cortex–> cortisol and then cortisol negative feedback to ant pit and hypothalamus
dopamine
from hypothalamus released prolactin from ant pit and targets breast tissue
posterior pit
DOES NOT RECIEVE TROPIC H THROUGH HYPopheasal pathway but hypothalamus send neurons down the pit stalk to post pit which releases oxytocin and ADH
oxytocin
uterine contractions during labor
lactation
ADH
antidietutic hormone or vasopressin- increases reabsorption of water in the kidneys
products of the ant pit
FLAT PEG
F- FSH
L-LH
A-ACTH
T-TSJ
P-Prolactin
E-Endorphins
G-GH
prolactin
mlk production in mammary glands
GH
growth hormone promotes growth in mescals and bone
ADH
secreted in response to blood volume
thyroid
controlled by thryoid stimulating homrone from ant pit
sets basal metabolic rate (release triiodothyronine- T3 and thyroxnine-T4) and promotes calcium homeotstais (calcitonin release
triiodothyronine- T3 and thyroxnine-T4
produced by follicular cells of the thyroid
make energy production more or less efficient alter utilization of glucose and fatty acids
deficiency in done == hypothyroidism
follicular cells produce C cells/parafollicular cells
which make calcitonin- decrease plasma Ca levels by increasing Ca excretion from the kidneys, decreasing ca from the gut or increasing storage of ca in the bone
parathyroid
produce parathyroid hormone (PTH)
antagonist H to Ca- increasing blood CA levels
negative feedback loop
activates vitamin D
glucagon fro alpha cells of the pancrase
increase glucose levels
insulin from the B cells from the pancrease
decrease blood gluc levels
ADH from the hypothalamus (released by post pit) increases blood volume and decreases blood osmoarlity
aldosterone from the adrenal cortex increases blood volume with no effect on blood osmoarlity. same with ANP from the heart
glucocorticoids
steroid H from adrenal glands that regulate glucose levels
cortsol and cortisone -and estrogens increase blood sugar in times of stress
under control by ACTH from the anterior pit.
mineralocorticoids
aldosterone- increases sodium resorption in the distal convoluted tube and collecting duct of nephron.
cortical sex hormones
androgens
adrenal medulla
makes epi and nor
sympathetic NS
glucagon
secreted during times of fasting when gluc is low- increases gluc production by triggering glycogensies
insukin
antagonist to glutton and secrete when blood glucose levels are high
cause hypoglycemia
diabtes
hyperglkycemia
type 1 diabetes
autoimmune destruction often B cells in the pancreases, low insulin production. type 2- receptor level resistance to the effects of insulin
somatostatin
inhibitor of both insulin dn glucagon
pineal gland
melatonin
monosacctdies three carbons, 4 C, 5C, 6C
triode, tetrose, pentose, hexose
glyceraldehyde
carbs with an aldehyde group as their most oxidized group, and with ketones
aldoses and ketoses
six C sugar with aldehyde
aldohexose
d-frustoce, d-glucose, d-galactose, d-mannose
know these structures
optical isomers
aka stereoisomers are compounds that have the same chemical formula - only difference by spatial arrangement in space
enatiomers
between stereoisomers that are nonidentical, non superimposable mirror images of one another
chiral C- 4 different things bonded to it
2 sugars that are in th same family (ketoses or aldoses and have the same number of C) that are not identical and not mirro rimages
diastereomers
epimers
subset of diastereomers that differentiations in cofirguation at exactly 1 chiral center
during hemiacetal and hemiketal formation, the carbonyl carbon becomes chiral and is termed the anomeric carbon
the OH sub on the carbon determines if the sugar molecule is alpha (axial and down tot eh CH2OH) or beta (up and equatorial)
exposing hemiacetal rings to water will cause them to
cycle between the open and closed form— mutarotation- alpha and beta
aldoses
considered reducing agents
hemiacetal ring
reducing sugar
Tollens reagent and Benedicts reagent
both used to detect the presence of reducing sugars
Tollen- reduced to produce a silvery error when aldelphydes are present
Benedicts- indicated by a reddish precipitate of Cu2O
tautomerization
refers tp tje rearrangement of bond in a compound, usually by moving a hydrogen and forming a double bond
enol
double bond and an alcohol group
starch
amylose (in plants) and amylopectin (glycosidic bonds- more soluble in solution bc branched so decreased intermoleulcaulr bonding between polymers and an increase with environment)
enzymes that cleave side activity will more likely cleave
glycogen because it contains more branching than amylopectin.
cell (plasma ) membrane
semipermeable phospholipid bilayer
chooses which particles to enter and leave- selective
fat-soluble cross easily, large and water soluble do not– by the bilayer and carriers
protect interior from exgernal
carbs associated with the membrane bound proteins create.
Glycoprotein coat
cell memebrane functions
regulate traffic in and out of the cell, communication and signaling. proteins embodied act as cell receptors during signal transuction
phosphopliids
move rapidly in the membrane through simple diffusion
lipid rafts
collection of similar lipids with or without associated proteins that serve as an attachment for other biomolcules- roles in signaling
flippasses
move lids between the membrane layers. this is hard with flipasse because the polar head group of the phospholipid must be forced through the non polar tail region in the interior of the bilayer.
membrane components- most plentiful to least
lipids (phosopholipid, cholesterol- fluidity to the layer) then proteins (channels and receptors in the transmembrane), carbs (glycoprotein coat and signaling molecules) and NA are absent
fatty acids
carbixlucic acids that contain a hydrocarbon chain and a terminal carboxyl group
triacylglycerides
stage lipids involved with human metabolic processes- three FA chains to a glycerol molecule
unsaturated fatty acid chains
healthier- one or more double bonds and exist at liquid form in room tmp- fluidity
kink
saturated fatty acids
soldis in room temp- less healthy
decrease fluidity of membrane
glycerophospholid
2 FA tails to a glycol and the last tail is a phosphate group
assemble into micelles (small vesicles) or ,liposomes (bilayer vesicles) due to hydrophobic interactions
secondd messengers, structure of membrane, phosphate group provides attachment point for soluble groups
spingolipids
not glycerol, have a hydrophilic regional’s dn 2 FA derived hyodrophobic tails (how they are simile to glycolipids)
cholesterol
regulates membrane fluidity and helps synthesized steroids
philic and phobiac regions
stability is derived from interactions with both of these regions that make up the bilayer
takes up space between phospholipids which prevents the formation of crystal structures and increasing flifuity at lower temperature
at high temperatures- cholesterol has the opposite effect by limiting movement between membrane and decreasing fluidiuty
waxes
cell memrbane of plants
extremely hydrophobic
long chain Fa and a long chain alcohol, contribeu to teh high melting point
stability and rigidity in the nonpolr tail region
protection/waterproof
fluid mosaic model
reset of 3 membrane proteins- transmamebrane, embodied and membrane-associated proteins
transmembrane proteins
pass completley through the bilayer
channels or receptors
embedded proteins
only with the interior (cytoplasm) or exterior (extracellular) surface of the cell
catalytic activity linked with nary enzymes
transmembrane and embedded are considered
integral proteins- associated with interior of the plasma membrane
membrane associated (peripheral) proteins
bound through electrostatic interactions with the lipid bilayer (at lipid rafters or transmembrane/embedded proteins)
ex. G protein next to the GPCR
signalling
