Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

54 Cards in this Set

  • Front
  • Back
how do cells vary?
in shape, function, ability to multiply, and mobility
fingerlike, hollow, tubular extensions of the cell membrane that increase surface area
molecular architecture of plasma membrane (types of molecules)
lipids- phospholipids, cholesterol, & glycolipids
proteins- integral/transmembrane
carbohydrates- in glycolipids & glycoproteins
lipid bilayer permeable to what?
impermeable to what?
permeable- lipid soluble substances like O2 and CO2

impermeable- water soluble substances like sugars, amino acids, ions (need channels)
what controls fluidity of plasma membrane?
fatty acids--> unsaturated makes a more fluid membrane; saturated makes it more rigid

and cholesterol
lipids with carbs attached to them

found in outer half of bilayer; contain monosaccharides
peripheral proteins
bound to surface of membrane, many on the interior
integral/transmembrane proteins
embedded in membrane/span it
serve as enzymes, carriers, channels, transporters, or receptors
proteins containing carbohydrates
carbohydrate role in lipid bilayer
project outward; cell-cell interactions & cell recognition
tight junctions
seal space between cells by fusing membranes; in epithelial sheets
spot-welds adjacent cells that reinforce tissue

between skin cells
gap junctions
couple cells electrically & chemically

important in cardiac muscle
network of interconnected membranes that form flattened sacs, canals, and vesicles; important to synthesize proteins & lipids
may be attached to ER or free in cytoplasm; made of rRNA & 80 ribosomal proteins; make proteins
flattened membranes formed from ER; near the nucleus; packages proteins; prominent in cells that secrete proteins AKA schtuff
oxidize glucose & fatty acids; lock energy into ATP
digest stuff with enzymes
bags of enzymes
abundant in liver & kidney
break down fatty acids, make cholesterol, make parts of myelin sheath
microtubule-organizing center; pair of centrioles
microfilaments & microtubules (function & made of?)
microfilaments- cellular movement; actin
microtubules- internal skeleton (& move organelles); tubulin
lipid droplets, glycogen granules, & melanin granules
# human chromosomes
46 (23 pairs)
physical processes that do NOT require energy from the cell
diffusion, facilitated diffusion (uses carrier proteins), osmosis
physical processes that require energy from the cell
active transport (uses carriers), endocytosis, exocytosis
types of cells that rarely divide
skeletal and cardiac muscle cells, differentiated neurons
cell cycle
M phase (PMAT), G1, S, G2
cytokinesis starts when?
during anaphase
consists of G1, S, G2
what splits cells?
contractile ring of microfilaments that forms over the equatorial plate
where are cell cycle checkpoints?
at G1, G2, and M
some checkpoints involve which tumor suppressor gene?
what phase do cells go into when they are withdrawn from the normal phases?
immortal strand hypothesis
new strands of DNA segregate together in daughter cells, so stem cells keep old DNA that is less likely to have errors
totipotent v. pluripotent cells
totipotent- can differentiate into anything (embryonic stem cells)

pluripotent- can differentiate into most things (bone marrow)
when cancer cells break away from the tumor, are carried to another part of the body, and form a secondary tumor
tumor suppressor genes
inactivation of these causes cancer (both copies must be inactivated for cancer to develop)
activation causes cancer
causes of activation/inactivation of tumor suppressor/proto-oncogenes
mutations, rearrangements of DNA, incorporation of viral DNA
tumor suppressor genes produce what?
proteins called cell cycle checkpoint determinants
what do cell cycle checkpoint determinants do?
arrest cell division, often in G1 (& sometimes in S) to allow cell to repair DNA
retinoblastoma tumor suppressor gene
loss of this gene causes retinoblastoma- due to the loss of a protein called pRB, which suppresses cell division

suppress gene by putting phosphate on it
p53 tumor suppressor gene
white blood cells that commit suicide (ex. of apoptosis)
consequences of improper apoptosis
too much- parkinson's, alzheimer's

too little- cancer
process of apoptosis
cells shrink & round up
DNA breaks up; chromatin condenses
nucleus breaks up
cell develops "blebs" on surface, which break away in apoptotic vesicles
vesicles are phagocytized by macrophages
"executioner enzymes" involved in apoptosis
proteases that break down cellular proteins & DNA
accidental cell death
cells lose shape, swell, lose function
membranes break down
cells & organelles undergo lysis
substances released cause inflammation
nuclear transfer cloning
nucleus removed from oocyte, donor cell fused using electric pulses
number of cells in body
> ten trillion (1 x 10^13)
number of cells that die each day
60-70 billion
3 types of endocytosis
receptor-mediated endocytosis
what is used in phagocytosis to kill engulfed particles?
superoxide (O2-)
example of exocytosis
release of neurotransmitters by neurons