cell lecture Flashcards
what are the two major divisions of the cell?
cell membrane and cytoplasm
what are the major components of the cytoplasm?
cytoskeleton, organelles, and cytosol
what are 3 functions of the cell membrane?
- keeps interior of cell separate from the external world
- actively regulates which substances enter/exit the cell
- ___ the cells from other cell structures
is the phospholipid bilayer hydrophobic, hydrophillic, or both?
both
in general, what is the function of the cholesterol in the cell membrane?
what are 3 major components of the cell membrane?
membrane proteins,
describe 5 functions of membrane proteins
describe three special extensions of the cell membrane that occur on some cells
contrast the function of microvilli and cilia
what is meant by simple diffusion
what types of substances are able to diffuse across the phospholipid bilayer? what
type of substances cannot simply diffuse across?
how is facilitated diffusion different from simple diffusion?
what are some substances that move via facilitated diffusion?
amino acids and carbs
what is the term for the diffusion of water?
osmosis
if a living cell is placed in a beaker of plain water, what will happen to the cell? why?
the cell will expand because the water concentration is
if a living cell is placed in a beaker of salty water, what will happen to the cell? why?
the cell will shrink because water follows salt
what is the fundamental difference between active transport and the other types of
transport we discussed?
what is the function of the sodium-potassium exchange pump?
what is the cytosol?
the fluid portion of the cytoplasm
what makes up the cytoskeleton?
filaments and microtubules
what are the three major functions of the cytoskeleton?
supports framework of the cell
strengthen cell and give it shape
help the cells itself move
list several of the cells organelles.
golgi
rough and smooth er
mitochondria
vesicles
cell membrane
cytoskeleton
what type of cell would be expected to have lots of mitochondria? what is the
function of this organelle?
cells that use a lot of energy like muscle cells. function is to provide energy to cell
what is the function of ribosomes? what are the two main places you find them?
function is to found on rough and smooth er and floating free in cytosol
what is the function of each rough and smooth er?
rough er- chemically modifies proteins
smooth er- synthesizes lipids
whose liver cells would probably have more SER, a child or an alcoholic? why?
alcoholic
what are the functions of the golgi apparatus?
proteins are are concentrated and packages into small membraneous sacs called vesicles for transport
how does the function of lysosomes differ from that of peroxisomes?
lysosomes- small sacs of digestive enzymes that destroy pathogens and recycle worn out or inactive parts of the cells
peroxisosomes- smaller sacs of enzymes but specialized to break down fatty and amino acids and neutralize hydrogen peroxide via catalase
after childbirth a woman’s uterus shrinks (atrophies) dramatically. what organelle is
largely responsible for this shrinkage?
lysosomes
describe the structure of the nuclear envelope.
made up of 2 phospholipid bilayers. outer layer merges into the er. pores for rna and protein to pass
what are the two major parts of a cell’s life called?
interphase and mitosis
what happens during interphase?
prepares for cell division by making more copies of dna and more organelles.
what is mitosis? what is the function of mitosis?
original nucleus divides to produce another genetical identical nucleus. function is to make new cells
what are the four major phases of mitosis?
interphase prophase metaphase telephase
why are spinal cord injuries so permanent?
because nerve cells dont undergo mitosis
what types of cells in the body divide especially frequently?
skin and gut cells
what’s the difference between a benign and malignant tumor?
benign glows slowly and does not spread
malignant grows fast and easily spreads
