Cell Biology Exam 1 Material

Functions of the plasma membrane

Cell integrity, permeability, adhesion, communication, and membrane potential

Three main components of plasma membrane

phospholipids, proteins, cholesterol

two main types of proteins in plasma membrane

integral and peripheral

phospholipids self assemble into (2)

mycelles, bylayers

what is this image of?

Epithelium

what does the blue line represent

plasma membrane of the basal surface

what does the pink area of this image represent (top left arrow)

Lipid raft

what does the dark purple area represent (left arrow)

non-raft area

what does the white represent (bottom arrow)

bacteral protein

as cholesterol is added to the gaps formed by unsaturated fatty acids the fluidity of the plasma membrane decreases

decrease

Move ions/molecules across the membrane with energy

pupps

Move ions/molecules across the membrane without energy

channels

Bind molecules in extracellular space

Receptors

Cell attachment to extracellular matrix (ECM)

Linker proteins

Attach cells to one another

Structural proteins

what side does the p face on (intercellular/extracellular)

intercellular

what side does the e face on (intercellular/extracellular)

extracellular

what face has most integral proteins

p face

this transport system only moves one molecule at a time

uniport

this transport system moves two different molecules the same direction

symport

this transport system moves two different molecules opposite direction

antiport

what molecules can move freely through the plasma membrane?

uncharged gasses, lipids, and lipid soluble molecules

name of channel that helps bring water into cell

aquaporins

facilitated diffusion is (faster/slower) than simple diffusion

faster

name of protein that is mutated in cystic fibrosis

CFTR

what is the purpose of the CFTR protein (cystic fibrosis) and what does it impact

Cl ion transport; water movement

two mechanisms of viscular transport

Endocytosis and Exocytosis

three methods of endocytosis

pinocytosis, phagocytosis, and receptor mediated endocytosis

This is the non specific uptake of fluid and small molecules

pinocytosis

helps with pinocytosis (3)

caveolin, flotillin, or actin cytoskeleton

This type of endocytosis is for the entry of specific molecules into the cell

receptor mediated endocytosis

molecule that helps with receptor mediated endocytosis

clathrin

name of protein that pinches off vesicle in receptor mediated endocytosis

dynamin

this is a disease caused by mutation in low density lipoprotein receptor

familial hypercholesterolemia

what is mutated in familial hypercholesterolemia

low density lipoprotein receptor

what does familial hypercholesterolemia lead to, what does it result in

excess cholesterol in blood stream, CAD or xanthomas

this is caused a mutation in the CFTR protein, what is a major symptom

cycstic fibrosis, accumulation of mucus in the lungs

this form of endocytosis is the engulfment of large particles

phagocytosis

what molecule helps phagocytosis

actin

inhibition of endocytosis also inhibits (and vice versa)

exocytosis

this is a receptor that can bind to a variety of different proteins and polysaccharides to identify many ‘large particles‘ for phagocytosis

C3b

most common fate of receptor and ligand after use

receptor recycled and ligand degraded

fate of LDL receptor

receptor recycled and ligand degraded

fate of transferrin receptor

both recycled

fate of EGF receptor

both degraded

fate of igA secretions

transcytosis

what is transcytosis

movement from one side of cell to the other

this image has only one nucleus how is this possible

multiple lobes

this cell has no nucleus

RBC

this cell has multiple nuclei

muscle cells

what are histones

small basic proteins that allow for tight packing of DNA

charge of histones

positive

heterochromatin

highly condensed inactive DNA

euchromatin

dispersed active DNA

what type of DNA is the green arrow pointing to

heterochromatin

what type of DNA is the blue arrow pointing to

euchromatin

what is this and what is its purpose

barr body; inactivation of the second X in females

the sorting and pairing of individual chromosomes based on size shape and color pattern

karyotype

how many histones are in one nucleosome

8

what is a nucleosome

DNA wound around histones

name all the proteins in a nucleosome (4×2)

H2A, H2B, H3, and H4

when are chromosomes visible

mitosis and miosis

this is important for rRNA processing and regulation of p53 expression

nucleostemin

the nucleolus contains mostly this

rRNA

spot for rRNA synthesis and ribosome assembly

nucleolus

space between inner and outer membrane of nuclear envelope

perinuclear space

the perinuclear space / cisterna is continuous with this structure

rough ER

provides structural support for nuclear envelope

nuclear lamina

purpose of nuclear lamina

sturcutral support and attachment site for chromatin

what filaments form the lattice like network for the nuclear lamina

lamins A and C

what intermediate filaments bind receptors in envelope

lamin B

what happens to the nuclear lamina during mitosis

disassembles then reforms

what can lamin mutations effect

striated and cardiac muscle, adipose tissue, nervous system, and premature aging

lamin mutation affecting adipose tissue can end up causing

lipodystrphy syndromes

lamin mutations affecting the nervous system can end up causing

peripheral neuropathy

what proteins make up nuclear pores (~100)

nucleoporins

small water soluble molecules can move via this through the nucelar pores

passive diffusion

Primary energy source for transport through the nuclear pore complex?

GTP

this sequence is recognized by importins in the nucleus

nuclear localization signal

this sequence is recognized by exportin in the nucleus

Nuclear Export Sequence

nuclear localization signal (NLS) is a sequence that is recognized by this to enter the nucleus

inportin

Nuclear Export Sequence (NES) is a sequence that is recognized by this to exit the nucleus

exportin

three types of cell cycle populations

static, stable, and renewing

in these cells no dicision occurs

static

in these cells division is sporadic

stable

in this cells regular division occurs

renewing

examples of static cells

neurons and cardiac myocytes

examples of stable cells

endothelial cells or fibroblasts

examples of slow renewing cells

smooth muscle of hollow organs

examples of rapid renewing cells

epithelial cells of GI tract

longest phase that is the period of cell growth (collect nutrients and synthesize proteins )

G1

phase where DNA synthesis occurs

S

phase with RNA and protein synthesis in preparation for mitosis

G2

stage where cells are no longer dividing

G0

protein expressed during g1 through mitosis (immunofluorescence)

ki67

protein expressed during S and G2 (immunofluorescence)

PCNA

protein expressed during S (immunofluorescence)

MCM2

given that the specimen is alive DNA in the S phase can be labeled with this for immunofluorescence

BrdU

in this phase there is a nuclear envelope and nucleolus, and chromatin is disbursed

interphase

in this phase DNA is condensed and the nuclear envelope and nucleolus is lost

prophase