cells and transport test Flashcards
cell membrain FUNCTIONS:
- Selectively Permeable or Semipermeable:
Regulates what enters/leaves the cell. - Separates inside cytoplasm from extracellular
(outside) environment. - Receives chemical messengers (hormones,
neurotransmitters, medicines) & passes the info to
the cell so it can respond.
CHOLESTEROL:
Located b/w the fatty
acids to stabilize &
strengthen the flexible cell
membrane.
PHOSPHOLIPID BILAYER:
– Determines what
molecules can enter &
leave the cell based on
their charge & size.
Anchor
Proteins:
keep
cells attached
forming tissues.
Enzymatic
Proteins:
catalyze
METABOLIC
reactions.
- Active site exposed to
substances in cytoplasm.
Identifier (Cell
Recognition) Proteins:
helps immune system
distinguish “self” vs.
foreign.
▪ Have unique carbohydrate
chains attached!
Receptor Proteins:
receive
chemical messengers & pass the
info to the cell so it can RESPOND!
Target Cells:
have specifically
shaped receptor proteins for only
certain chemical messengers.
Hormones &
Neurotransmitters:
types of
chemical messengers that bind
to specific receptors in order to
transmit a message.
Channel Proteins:
provides a
hydrophilic channel so charged
substances can cross the
membrane.
Carrier Proteins:
change shape
while shuttling SPECIFICALLY
SHAPED substances across the
membrane.
Living Cells:
H2O = ~98%
Solutes = 2%
(glucose, salt, O2, CO2
, amino
acids, etc.)
CONCENTRATION GRADIENT:
Difference in
solute [ ]
b/w 2 areas.
EQUILIBRIUM:
Solute & H2O
molecules are
equally
distributed, &
continue moving
evenly in all
directions.
DIFFUSION:
Movement of molecules
from high 🡪 low [ ]
w/out use of ATP
energy (usable energy).
Simple diffusion
through the phospholipids: nonpolar
molecules (small lipids, steroids, gases) can pass b/w the
phospholipids because they can interact with the
nonpolar fatty acid tails!
Facilitated Diffusion
through transport proteins:
charged substances (glucose, H2O, ions, polar molecules)
CANNOT interact w/ nonpolar fatty acid tails, SO they
must diffusion through a transport protein.
WHAT ABOUT LARGE POLYMERS, LIKE
PROTEINS OR POLYSACCHARIDES?
TOO LARGE to diffuse across the membrane…
SO they must be hydrolyzed into monomers & then can
diffuse across the membrane.
OSMOSIS:
PASSIVE TRANSPORT OF
WATER
HYPERTONIC SOLUTION:
solution that has a HIGHER [ ]
of solute.
ISOTONIC SOLUTION:
the solutions outside of cell
and inside the cytoplasm
have an equal solute [ ].
HYPOTONIC SOLUTION:
solution that has a lower [ ] of
solute.
Plasmolysis:
cell membrane
pulls away from cell wall as
water leaves by osmosis.
Turgor Pressure:
the entering
water fills the central vacuole,
& cell membrane presses
against cell wall.
Maintains upright position of the
plant!
ACTIVE TRANSPORT:
molecules pumped from Low to High [ ], w/ the
use of ATP energy! (usable energy that fuels life
functions)
ALL LIVING CELLS:
- Maintain homeostasis (dynamic
equilibrium)
2.Carry out metabolism:
3.Carry out Life Functions!
LIFE FUNCTIONS: 3 R’s
Regulation – control/coordination of all life functions.
Reproduction – production of new individuals of a species.
Respiration – breaking down glucose (organic) to transfer its
energy to ATP molecules (containing usable energy that fuels
life functions).
LIFE FUNCTIONS: 3 GENTS
LIFE FUNCTIONS: 3 R’S GENTS
Growth – increase in cell size and cell #.
Excretion – elimination of cellular waste (nitrogenous wastes, carbon
dioxide, water, salt, etc.)
Nutrition – 1) Ingestion – taking in food (heterotrophs only) 🡪
autotrophs make their own food!
2) Digestion – breaking down food.
3) Egestion – eliminate solid waste.
EUKARYOTES:
Have a nucleus &
mitochondria!
Many specialized &
complex organelles.
DNA on chromosomes
inside the nucleus.
Ex. Plants, animals, fungi &
protists.
PROKARYOTES:
No nucleus, no
mitochondria.
Very few organelles.
Cell is small & simple.
DNA/single chromosome
floats in cytoplasm (in
nucleoid region).
Ex. Bacteria (Archaebacteria &
Eubacteria)
SINGLE-CELLED ORGANISM:
Organism made of 1 cell.
Ex. Bacteria & protists such as ameba,
euglena, paramecia
MULTI-CELLED ORGANISM:
Organism made up of many cells!
Ex. Animals, plants, some fungi
Organization of LIFE in a Multi-celled Organism –
Smallest Largest
cell 🡪 tissue 🡪 organ 🡪 organ system 🡪 organism
CELL SPECIALIZATION IN MULTI-CELLED
ORGANISMS:
Cells use different parts of
their genetic code to
perform specific functions
w/in an organism!
Specialized cells take on
unique shapes & roles to
maintain homeostasis!
ORGANELLES:
Structures w/in a cell that carry out specific life functions.
NUCLEUS:
Controls cell activities
(contains chromatin/
chromosomes).
CHROMATIN (CHROMOSOMES):
contains instructions
for making proteins!
* In prep. for cell
division…the loose,
thread-like
chromatin condenses
into tightly packed
chromosomes!
NUCLEOLUS:
Makes
ribosomes.
CENTRIOLES:
Aid in cell division.
(In animal cells ONLY)
NUCLEAR MEMBRANE (ENVELOPE):
Regulates what
enters/leaves the nucleus.
SMOOTH ENDOPLASMIC RETICULUM (SER):
- Makes phospholipids!
- Transports substances.
- Decreases toxins.
ROUGH ENDOPLASMIC RETICULUM (RER):
Modifies proteins made
by ribosomes & sends
them to the Golgi
Apparatus.
RIBOSOMES:
make proteins (protein
synthesis).
GOLGI APPARATUS:
Modifies proteins (adds
carbohydrate chains or lipids to
them) & packages them for
exocytosis or cell use!
VACUOLE:
Stores water,
wastes, proteins,
salts, food, etc.
until they are
used or
eliminated by
the cell.
LYSOSOMES:
Contain digestive
enzymes that break
down food, worn
out organelles &
foreign substances.
(In animal cells ONLY)
MITOCHONDRIA:
Conducts Cellular Respiration 🡪
breaks down glucose & transfers
the energy to ATP which fuels cell
activities!
CYTOPLASM:
Fluid-like substance
that transports
materials & holds
organelles “loosely”
in place.
CELL (PLASMA) MEMBRANE:
Selectively permeable,
receives chemical
messages & separates
internal from external
environment.
CENTRAL VACUOLE:
Stores water & presses
against the cell
membrane & cell wall,
creating Turgor Pressure!
CELL WALL:
Provides support &
rigidity to the cell.
CHLOROPLAST:
Conducts
Photosynthesis:
absorbs light, H2O
& CO2
to make
GLUCOSE (food) &
O2
CYTOSKELETON:
Network of protein
filaments - help
maintain cell shape
& are involved in
cell movement.
MICROTUBULES:
Hollow tubes of protein.
* Helps keep cell shape.
* Serve as “tracks” that organelles
can move along.
* Help separate chromosomes
during cell division.
* Form “hair-like” projections (cilia &
flagella) from the cell’s surface that
aid in locomotion of single-celled
organisms.
MICROFILAMENTS:
Long thin protein fibers.
Aid in cell support &
movement.
