Exam 1 Physiology IUPUI Dr. Fahim

Levels of organization

cell, tissue, organ, organ system, organism

Cells are classified into 4 groups:

neurons, muscle cells, epithelium, and connective tissue

neurons

Short and rapid communication, some can process information

neuron to brain length

long path

neuron to spinal cord length

short path

dendrites

recieve information

axon terminal

send information out

soma

axon

muscle cells

specialized cells to contract

types of contraction

voluntary and involuntary

muscle types

skeletal, cardiac, smooth

skeletal is under control of

somatic nervous system

smooth and cardiac are under the control of

autonomic nervous system

epithelium

layer of cell which separates internal from external environment

when epithelium lines hollow organs or vessels it is called:

endothelium

glands are formed by

epithelium

function of glands

to produce a product; exocrine: secrete things outside, endocrine: secrete product into blood.

connective tissue

characcterized by extracellular matrix, anchored or support things

interstitial fluid

surrounds all types of cell except blood cells

plasma

surrounds the blood cells

membranes are semipermeable

Allow some things to pass through when restricting others

what percent of your body weight is TBW?

60%

TBW (total body water) is consisted of

40% ICF, 20% ECF which is (80% interstitial fluid, 20% plasma)

homeostasis

maintaining a constant internal environment with a variable external environment. (ex. eat a dessert, BS high, your beta cells in the pancreas will secrete insulin which takes BS from blood and stores in cells, BS back to normal)

4 structures enabling homeostasis

receptors, integrating centers, effectors, signals

pathophysiology

when you disrupt homeostasis

regulated variable

aspect which is maintained (ex. blood glucose concentration)

Set point

most normal number (blood glucose is 100 mg, although this varies person to person)

error signal

difference between acceptable value and what it actually is

negative feedback

Stopping process because we reached baseline number (Ex. BS high, send info to pancreas, release insulin, insulin will store BS in cells, lower blood sugar, normal, tell STOP WE HAVE REACHED NORMAL)

Receptors

sensors that detect stimuli

thermoreceptors

temperature

chemoreceptors

ph of blood

baroreceptors

blood pressure

mechanoreceptors

vibration or movement

osmoreceptors

concentration

photoreceptors

light

integrating center

orchestrate an appropriate response

effector cells

responsible for body responses (Ex. muscles or glands)

signals

allows cells to communicate; afferent (going to the integrating sensor) and efferent (coming out of)

positive feedback

the change in the variable is reinforced, goes to completion. (ex. pituitary gland will secrete luitinizing hormone that will reach ovaries, increasing estrogen secretion. Release LH - increase estrogen. Release LH - increase estrogen. until egg is mature enough.)

All cells in the human body are derived from

fertilized ovum

Plasma membrane

barrier between the cell and external environment. ECF: fluid outside cell, ICF: fluid inside cell

Plasma membrane fluid mosaic model includes

phospholipid bilayer, cholesterol, membrane proteins, and membrane carbohydrates.

amphipathic

Having both a hydrophilic side and a hydrophobic side

Lipid soluable =

nonpolar, lipophilic, and hydrophobic

easily move accross lipid bilayer

water soluable =

polar, lipophobic, hydrophilic

If a membrane is hydrophobic __ can pass through the membrane easily

lipids

covalently bound to membrane lipids or proteines are

glycoproteins and glycolipids, function cell recognition

Nucleus

transmission and expression of genetic information

Cytosol

Fluid portion of cytoplasm

Cytoplasm

fluid and organelles

Rough ER

ribosomes on surface; synthesis of proteins to be packaged into vesicles

Smooth ER

lipid synthesis, storage of calcium, detoxification through enzymes

___ of the rough and the smooth ER are connected

lumens

where are ribosomes made

nucleolus

golgi

packaging of proteins and direct them to their destination, post translational processing of proteins.

mitochondria

generates ATP

lysosomes

An organelle containing digestive enzymes, degrade extracellular debris through endocytosis and exocytosis.

peroxisomes

degrade certain waste molecules; contain enzyme called catalase. H2O2 -> H2O + O2

-ase

enzyme

ribosomes

rRNA and proteins, made up of two subunits, necessary for protein synthesis.

vaults

barrel-shaped organelles, may function in the transport of molecules between nucleus and cytoplasm. Important in apoptosis. possess vault RNA (vRNA).

centrioles

pared cylindrical structures, perpendicular to each other. Function in development of the mitotic spindle.

cytoskeleton

support and structure, transport of materials, suspension of organelles, formation of adhesions with other cells, contraction, and movement.

to be able to contract you must have

actin and myosin

microfilaments

7 nm diameter, common type is actin

intermediate filaments

10 nm diameter, common types myosin and keratin

microtubules

25 nm diameter, function as mitotic spindle and major component of cilia and flagella.

protein synthesis

Theres no ___ in RNA

thiamine. RNA has uracil but not thiamine.

transcription

DNA to pre mRNA, occurs in the nucleus

translation

mRNA to protein, occurs in the cytoplasm

Gene

portion of dna holding the genetic code

Triplet

a nucleotide sequence that codes for a specific amino acid, has 3 bases

a triplet is transcripted into a

codon, has 3 bases

initiation codon

for translation!!! not transcription. Where you START translation

-promotor sequence

splicing

the process of removing introns and reconnecting exons in a pre-mRNA (think introns=trash, want exons)

elongation

addition of amino acids to the polypeptide chain; continues until it reaches a stop codon

termination codon

One of the three codons (UAA, UAG, UGA) that signal the termination of translation of a polypeptide.

-terminator sequence

RNA polymerase

Enzyme similar to DNA polymerase that binds to DNA and separates the DNA strands during transcription

capping and poly a tail

protect from degrading, support

what codon starts translation

AUG (think "Are You Good?")

tRNA

transfer RNA; type of RNA that carries amino acids to the ribosome

-Charged: amino acid bound

-Free: no amino acid bound

-two binding sites: P site, A site

P site

holds the tRNA with the LAST amino acid added to the polypeptide chain

A site

holds tRNA with the NEXT amino acid to be added to the polypeptide chain

post translational modification

changes made to polypeptides following translation

-folding

-cleavage

leader sequence

Leads the protein to where it should be then is removed. Can lead to the nucleus, peroxisome, or mitochondria.

post transcriptional modification

-splicing, removing introns

alternative splicing

Some exons are removed or joined in various combinations. (ex: 1-3-2, 2-1-3, 3-2-1)

protease

enzyme that degrades proteins

Proteasomes contain proteases

ubiquitin

Marks proteins for degradation, a chemical tag.

metabolism

the sum of all chemical reactions occurring in a cell

catabolic reactions

break down molecules

Anabolic reactions

build molecules

Is hydrolysis catabolic or anabolic?

Ex) sucrose + H20 -> glucose + fructose

Catabolic

is condensation anabolic or catabolic?

Ex) glucose + fructose -> sucrose + H2O

anabolic

Is this reaction phosphorylation or dephosphorylation? Anabolic or catabolic?

ADP + Pi -> ATP + H2O

phosphorylation, anabolic

Is this reaction phosphorylation or dephosphorylation? Anabolic or catabolic?

ATP + H2O -> ADP + Pi

dephosphorylation, catabolic