Chapter 6- A Tour of the Cell Flashcards
surface area:
cell membrane
limiting factor to cell size
surface area
volume:
cytoplasm
cell membrane is selectively permeable- if the volume of the cell is to large:
the cell membrane cannot maintain the cytoplasm (cell will split into 2 smaller cells
Robert Hooke
cork, named the cell (prison cells)
Matthias Schleiden
all plants are made of cells
Theodore Schwann
all animals are made of cells
Rudolph Virchow
cells come from preexisting cells
cell theory:
all living things are made of cells
new cells come from preexisting cells
prokaryotic cells
lack a well defined nucleus and most membrane bound organelles
1-10 um
eukaryotic cells
well defined nucleus and membrane bound organelles
10-100 um
endosymbionic theory (definition)
describes how eukaryotes emerged from the prokaryotes
endosymbionic theory (process)
several prokaryotic cells engulfed each other and lived in a symbiotic (mutualistic) relationship
symbiosis-mutualism
both benefit
termite and protist in intestine
symbiosis- commensalism
one benefit from another (one not affected)
sea anemone and clownfish
symbiosis- parasitism
one benefit, one harmed
tapeworm in humans
organelles
little organs
sub cellular structures that have a specific shape and function in the cells
nucleoplasm
all living material inside the nucleus
cytoplasm
all living material from the nuclear membrane to the cell membrane
cytosol
semifluid medium in which the organelles are suspended
plasma membrane
“cell membrane”
functions as a selective barrier that allows certain substances in and out of the cell
semi-permeable (selectively permeable)
nucleus
contains most of the genes that control the eukaryotic cell
other organelles that contain genes (besides nucleus)
mitochondria and chloroplasts
nuclear lamina
netlike membrane made of protein filaments on the inside of the nuclear envelope
helps nucleus maintain shape
nuclear pores
small holes in the nuclear envelope that allow substances to enter and leave the nucleus
chromatin
genetic material made of DNA and histone protein
granular form
chromosomes
made of chromatin
thread-like structures made of DNA and histone protein
number of average chromosomes in humans
46
somatic cells
regular body cells
gametes
sex cells
23 chromosomes
nucleolus
small round structure found inside the nucleus
components of the ribosomes are synthesized and assembled
ribosomes
organelles that produce (synthesize) proteins
most numerous organelle in the cell
free ribosomes
found floating in cytosol
used by cell itself
bound ribosomes
stretched to rough ER
these proteins are usually exported from the cell or used in the cell membrane
endoplasmic reticulum
network of membranous tubules
internal compartments of ER
cisternae (cisternal region)
smooth ER
synthesis of lipids, metabolism of carbohydrates, detoxification of drugs and alcohol
(more smooth ER in liver cells of an alcoholic)
detoxification of alcohol
adding a hydroxyl group to drugs or alcohol making them more soluble and easier to flush from the body
and individual can develop more tolerance to certain drugs when
the cells of the liver produce more smooth ER
many smooth ER in:
testes and ovaries
secrete hormones for male and female characteristics
rough ER
has ribosomes attached to it
secrete proteins that have been modified and produce proteins for the cell membrane
organ rich in rough ER that produces insulin (enzyme that reduces blood sugar levels)
pancreas
rough ER (diagram)
produces secretory proteins that leave the ER in membrane vesicles that bud like bubbles from the region called the transitional ER
Golgi apparatus
products of ER modified and stored here
series of flattened, membranous sacs(called cisternae)
opposite ends of Golgi differ in thickness and molecular composition
cis face (Golgi)
receiving side
trans face (Golgi)
exporting (shipping) side
step 1 (Golgi)
vesicles move from ER to Golgi
step 2 (Golgi)
vesicles coalesce to form new cis Golgi cisternae
step 3 (Golgi)
cisternal maturation: Golgi cisternae move in a cis to trans direction
step 4 (Golgi)
vesicles form and leave Golgi, carrying specific proteins to other locations or to the plasma membrane for secretion)
step 5 (Golgi)
vesicles transport specific proteins backward to newer Golgi cisternae
step 6 (Golgi)
vesicles also transport certain proteins back to ER
products of Golgi
hyalcronic acids
sticky substance that makes animal cells stick together
products of Golgi
lipoproteins
attaches a lipid to a protein
products of Golgi
glycoprotein
carbs attached to proteins
lysosomes
hydrologic enzymes that are used to digest all classes of macromolecules
will fuse with a food vacuole and digest it’s contents
can digest old or worn out organelles
autodigestion
when lysosomes opens up and digests entire cell (happens when cell is old or damaged
vacuoles
rare (not many) in human cells
food vacuole
in Protista
formed by phagocytosis (digested by lysosomes)
contractile vacuole
pump excess water out of cell (in protista
central vacuole
in plant cells
enveloped by tonoplast
filled with cell sap
tonoplast
membrane in central vacuole
cell sap
mostly water
also includes stored food, salt, waste, and poisons
mitochondria
sites of cellular respiration
cellular respiration
catabolic process that produces ATP
ATP
adenosine tri-phosphate
cristae (folds in mitochondria)
increase in surface area for ATP production
cells rich in mitochondria
muscle cells
chloroplasts (plastid)
contains chlorophyll
membranes that allow for photosynthesis
plants and some protists contain them
amyloplast (plastid)
organelles that store amylopectin
amylopectin
most common form of starch in plants
chromoplast
contains all of the plant pigments other than chlorophyll
xanthophyll, anthocyanin, carotene
xanthophyll
yellow chromoplast found in bananas
anthocyanin
red chromoplast found in beets
carotene
yellow/orange chromoplast found in carrots
peroxisome
contains catalase (enzyme) to break down H202 (hydrogen peroxide)
organ high in peroxisome (and therefore rich in catalase)
liver
equation for peroxisome
H202 (metabolic waste) + catalase=
H20 + 02
cytoskeleton
cells skeleton
network of fibers throughout the cytoplasm
microtubules (in cytoskeleton)
thickest and most rigid of the fibers
made of tubulin protein
help cell maintain shape and anchor the organelles (bones)
intermediate fibers (in cytoskeleton)
medium sized fibers
proteins from the keratin family
main part of nuclear lamina
also help cell maintain it’s shape
microfilaments (in cytoskeleton)
thinnest and smallest fibers
made of actin protein
cause movement in cell
cyclists and cytoplasmic streaming
centrosome
region located near nucleus where the ends of the microtubules are located
centrioles
9 sets of triplet microtubules arranged in a ring
appear just before cell Dickson and used during cell division
9 and 3 arrangement of microtubules
centrioles
cilia and flagella
appendages used for movement
9 doublets of microtubules
9 and 2 arrangement of microtubules
cilia and flagella
cilia
hair like appendages
on amoebas
flagella
tail like appendages
on sperm
dynein protein in microtubules
changes it’s conformation and causes movement
powered by ATP
motor proteins
stretch to receptors on organelles and “walk” the organelle along the microtubule
makin my way downtown
plasmo desmada (plant cells)
cell junction
open channels in cell walls of plants through which strands of cytosol can pass to and from adjacent cells
tight junction (animal cell$)
cell junction
continuous belts around cell membranes of neighboring cells that are fused forming a seal that prevents leakage
(found in human intestines)
desmosomes (animal cells)
cell junction
function like rivets fastening cells together in strong epithelial sheets
gap junctions (animal cells)
cell junction
connections that provide cytoplasmic channels between animal cells
rapid transportation of salts and sugars
gap junctions (rapid transportation of salts and sugars)
muscle cells (especially of the heart) and allows for rapid ion flow)
