size and shape of cells, cells, cell organelles Flashcards
Surface area must be large enough to all the cell to:
obtain resources
eliminate waste
acquire/dissipate thermal energy
exchange chemicals/energy with environment
what SA:V ratio do small cells have? what benefits does this have?
large
efficiently exchanges materials
as cells increase in volume
the relative SA:V decreases
demand for resources increases
rates of chemical exchange may then be inadequate for cell size
what structures are necessary for cells to exchange materials
complex cellular structures (membrane folds)
as organism increase in size
SA:V decreases
affects rate of heat exchange with environment
why must cells remain small?
maintain a large SA:V ratio
why is a large SA:V ratio beneficial?
allows increased rates of chemical exchange between cell and environment
Surface Area of a Sphere
SA = 4(pi)r2
Surface Area of a Rectangular Solid
SA = 2/h + 2/w + 2wh
Surface Area of a Cylinder
SA = 2(pi)rh + 2(pi)r2
Surface Area of a Cube
SA = 6s2
Volume of a Sphere
V = 4/3 pi r^3
Volume of a Rectangular Solid
V=lwh
Volume of a Cylinder
V=(pi)r^2 h
Volume of a Cube
V = s^3
Cell fractionation
take apart cells, separate major organelles
Ultracentrifuge
applies a force 1,000,000x force of gravity to separate cell organelles
most dense organelles go to bottom
nucleus function
control center of cell
what does the nucleus contain
genetic material
nuclear envelope
double membrane with pores, surrounds nucleus
continuous with rough er
Nuclear side of envelope lined with a network of protein filaments (maintains shape)
nuclear pores function
control what enters/leaves nucleus
chromatin
complex of DNA + proteins; makes up chromosomes
in nucleus
nucleolus
region where ribosomal subunits are formed
in nucleus
ribosomes function
synthesize proteins according to mRNA sequence
what are ribosomes composed of
ribosomal RNA + protein (Large subunit + small subunit)
what forms of life are ribosomes found in
all, reflects common ancestry
Free ribosomes
float in cytosol, produce proteins used WITHIN the cell
Bound ribosomes
attached to ER, make proteins for EXPORT from cell
ribosomes are the cell’s:
proteins factories
ENDOMEMBRANE SYSTEM:
function
Regulates protein traffic & performs metabolic functions
ENDOMEMBRANE SYSTEM includes
Nuclear envelope, ER, Golgi, Lysosomes, Vacuoles, and Plasma Membrane
ENDOPLASMIC RETICULUM
Network of membranes and sacs that are continuous with nuclear envelope
Rough ER
ribosomes on surface
rough er functions
elps to “compartmentalize the cell”, package proteins for secretion, send transport vesicles to Golgi, make replacement membrane
smooth er
no ribosomes on surface
smooth er functions
synthesize lipids
detoxification: drugs & poisons in liver
store Ca2+ in muscle cells to help regulate muscle contraction
metabolize carbs
golgi apparatus
Membrane bound structure of a series of flattened stacks of membranes sacs
Cisternae
flattened membranous sacs that receives vesicles
in golgi
Cis Face
receives vesicles
trans face
ships vesicles
golgi functions
modify, store, & ship proteins
help correctly fold and make chemical modifications to newly synthesized proteins
packages these proteins for protein trafficking
lysosomes structure
vesicles of digestive hydrolytic
enzymes
lysosomes function
intracellular digestion
digests macromolecules
cleans up broken down
organelles, recycles organic material
hydrolytic enzymes facilitate apoptosis (programmed cell death)
can be used to kill cells when they are supposed to be destroyed
programmed development
control of cell growth
some cells have to die for proper development in an organism
where are lysosomes synthesized and transferred to?
synthesized by rER, transferred to Golgi
where are lysosomes found
animal cells
phagocytosis
cellular digestion
Lysosomes fuse with food vacuoles
polymers digested into monomers
pass to cytosol to become nutrients of cell
lyso
break apart
-some
body
diseases of lysosomes are often _ because
fatal:
digestive enzyme not working in lysosome
picks up biomolecules, but can’t digest one
lysosomes fill up with undigested material
grow larger & larger until disrupts cell & organ function
apoptosis
auto-destruct” process
lysosomes break open & kill cell
PEROXISOMES structure
digestive enzyme sac
PEROXISOMES functions
break down fatty acids to sugars
detox cell of alcohol and other poisons
where are PEROXISOMES found?
plants and animals
what chemical reaction happens in PEROXISOMES?
Catalase enzyme breaks down hydrogen peroxide (H2O2) resulting in water and oxygen
Glyoxysomes function
convert oils to sugars in seeds for energy source
VACUOLES structure
Membrane-bound vac
VACUOLES function
storage of food, water, minerals
what vacuole do plants have? why is this important?
large central vacuole – stores water, ions
stockpile proteins, dispose of byproducts, hold pigments, store defensive compounds
Food vacuoles
form by phagocytosis and fuse with lysosomes
Contractile vacuoles in freshwater protist function
pump excess water out/maintain water and salt balance
Large vacuole reduces
area of cytosol, so SA/V ratio increases
VACUOLES in plants functions
storage
stockpiling proteins or inorganic ions
depositing metabolic byproducts
storing pigments
storing defensive
compounds against
herbivores
selective membrane
control what comes
in or goes out
Vesicles function
transportation
Central vacuoles
in many mature plant cells,
Stockpile proteins, hold pigments,
Store defense compounds
cells must convert what when it enters the cell? why
energy, to use for work
mitochondria
from glucose to ATP
atp is
active energy
chloroplasts
from sunlight to ATP & carbohydrates
carbohydrates are stored
energy
chloroplasts are only found in
plants (plastids)
chloroplasts function
site of photosynthesis
converts light energy into chemical energy
store chlorophyll
chlorophyll
captures light energy
in chloroplasts
why are chloroplasts in internal sac membranes
increase surface area for
membrane-bound enzymes that synthesize ATP
amyloplasts
store starch in roots & tubers
chromoplasts
store pigments for fruits & flowers
chloroplasts location
in leaves, other green
structures of plants &
in eukaryotic algae
carbon dioxide + water + energy –>
glucose + oxygen
main function of mitochondria
site of ATP production by oxidative phosphorylation
mitochondria structure
Double membrane - “compartmentalization” for different metabolic reactions
outer - smooth
inner - highly convoluted, forming folds… increase surface area for membrane bound enzymes for synthesize ATP!!
mitochondria functions
site of cellular respiration
Use oxygen to make ATP and breaks down carbohydrates
Generate ATP in presence of Oxygen (aerobic respiration)
Break down larger molecule into smaller to generate energy= catabolism
what types of cells contain mitochondria? how many are in a cell? what is this number correlated to?
eukaryotic
1 large mitochondrion/100s-1000s small mitochondria
aerobic metabolic activity
more activity = more _
energy = more mitochondria
what cells have a lot of mitochondria?
active cells (muscle, nerve)
ENDOSYMBIONT THEORY
Mitochondria & chloroplasts share similar origin
Prokaryotic cells engulfed by ancestors of eukaryotic cells
ENDOSYMBIONT THEORY evidence
structure
Transform energy
Have own ribosomes & circular DNA, enzymes
Reproduce independently within cell
Semi-autonomous (move, divide, change shape)
role of nucleus
control center of cell
rough er has
ribosomes
ribosomes function
site of protein synthesis
2 things smooth er is responsible for
makes lipids, breaks down toxins
golgi: newly made proteins are transported here and can go
lysosome
vacuole
lysosomes break down
unused materials
vacuoles are important for
storage
mitochondria makes
atp
chloroplasts make
sugar
what two things are ribosomes made up of?
proteins and rRNA
where are ribosomes synthesized
nucleolus
how many subunits make up a ribosome
2
why does mRNA go through the middle of a cell
tRNA to a protein
what is the ER attached to
nucleus
rough ER has ribosomes on it so it can
synthesize proteins
smooth er is where what happens
lipids are synthesized
function of the ER is to be a _ so cells can __
lattice
build things
what did camillo golgi discover
discovered golgi, stain cells
golgi complex purpose
takes information that is made in the ER and moved to cellular UPS
3 purposes of lysosomes
has digestive materials, kills cells, breaks down unwanted materials
why is the folding on mitochondria cristae important
increases surface area to make more ATP
2 purposes of valuoles
storage, cell growth
chrolorplast main puporse
photosynthesis
cell membrane found in what cells?
plant and animal
cell wall found in what cells?
plant
nucleus found in what cells?
plant and animal
ribosomes found in what cells?
plant and animal
ENDOPLASMIC reticulum found in what cells?
plant and animal
golgi found in what cells?
plant and animal
lysosomes found in what cells?
animal
vesicles found in what cells?
plant and animal
central vacuole found in what cells?
plant
peroxisome found in what cells?
plant and animal
mitochindria found in what cells?
plant and animal
chloroplasts found in what cells?
plant
