ch 3.1-3.5 Flashcards
what is biology
study of life
what can living organisms do
-regulate their internal environment
- grow
- uptake nutrients
- eliminate waste
- reproduce
- respond to external stimuli
what are living organisms made of
cell
what is a cell
structural and functional unit of all living organisms enclosed in a membrane
what is a cell made up of
plasma membrane
cytoplasm
nucleus
what does a cell do
provide structure for the body
provide nutrients from food
convert nutrients into energy
carry out specialized functions
contain hereditary materials
multicellular organisms have
organ systems
what can be seen in a light microscope as the 3 major regions of a cell
nucleus
cytoplasm
plasma membrane
what is the plasma membrane/ what is it made up of
lipid bilayer that has proteins embedded in it
what lipids are the lipid bilayer made of?
phospholipids-contains phosphorus
cholesterol
glycolipids-attached to carbohydrates
where is the plasma membrane
outside of the cell
what does the plasma membrane do
separates cell content
provides a protective layer
maintains a resting potential
controls what goes in and out of the cell (selective permeability)
helps identify the cells to other cells
signals cell-to-cell interaction
the plasma membrane mostly consists of
phospholipids…in a bilayer and proteins…mostly glycoproteins
what proteins are in the plasma membrane
integral
peripheral
what is an integral protein
protein embedded in plasma membrane
what does an integral protein do
moves molecules across the membrane
where is an integral protein
in plasma membrane
what is a peripheral protein
biologically active molecules formed of amino acids and interacts with the surface of the lipid bilayer of cell membrane
where is the peripheral protein
loosely attached to the exterior or interior surface of the membrane.
ex. glycoprotein
what does a peripheral protein do
attached to integral protein and provides framework for the plasma mebrane
moves stuff from out into the cell
what is selective permeability
plasma membrane allowing some substances to move into and out of the cell but restricts others
some integral proteins form what?
ion channels…K+ can now move in and out of the cell
what can pass through the plasma membrane through integral proteins
small and medium sized water-soluble material
ions through forming an ion channel
what is a carrier
transporter
move a substance from one side of the membrane to the other by changing shape
where is a carrier
in plasma membrane its a protein
what is a receptor
an integral protein
what do receptors do
recognize and bind a specific molecule that controls a cellular function
example of cell identity markers
membrane glycoproteins and glycolipids
what does a cell identity marker do
enable a cell to recognize other cells of its own kind during tissue formation
recognizes and responds to potentially dangerous foreign cells
what is intracellular fluid
the cytosol
where is ICF
fluid in a body that is contained inside body cells
what does ICF do
home of cytoskeleton
moves material around the cell
what is ECF
fluid outside body cells
where is extracellular fluid
in the microscopic spaces between the cells of tissues…called interstitial fluid
what does ECf do/is the exchange of
the exchange of substances between the cells and the rest of the body
what is the nucleus
control centre of the cell
holds genetic info
what is the nucleus made of
chromatin -loosely dispersed DNA (cell not dividing)
chromosome -condensed chromatin
where is the nucleus
in cells
what does the nucleus do
controls cells-structure and activity
stores genetic info
produces ribosomes in nucleoli
what is cytoplasm composed of
cytosol and organelles
cytosol
liquid portion where organelles reside
-water, proteins, lipids, carbs etc
what is cytosol
liquid portion of the cytoplasm that surrounds organelles and is about 55% of the total cell volume
what is cytosol made of
75-90% water and dissolved solutes and suspended particles
what does cytosol do/waht is it the site of
site of many chemical reactions that maintain cell structures and allow for cellular growth
where is cytosol
in cytoplasm
what does the cytoskeleton do
structural support/ framework for the cell
scaffold to determine cell shape and organize its contents
aids in movement of organelles within a cell, of chromosomes during cell division and whole cells such as phagocytes
what is the cytoskeleton/what is it made of
network of three diff types of protein filaments
where is the cytoskeleton
in the cytosol (cytoplasm)
3 diff protein filaments of the cytoskeleton
microfilament
intermediate filament
microtubules
what is a microfilament
protein filament
what does a microfilament do
provide mechanical support
generate movements-muscle contraction, cell division and cell locomotion
anchors cytoplasm to integral proteins
provide support for microvilli-they increase SA of a cell
where is a microfilament
cytosol
what is an intermediate filament
protein filament
where are intermediate filaments found
found in parts of the cell subject to tension (in cytosol)
what do intermediate filaments do
hold organelles in place
attach cells to eachother
what do microtubules do
determine cell shape
movement of organelles
migration of chromosomes during cell division
movements of cilia and flagella
what is a microtubule
largest of cytoskeletal components, long hollow tube
where are microtubules found
in cytosol, type of protein filament of the cytoskeleton
what is an organelle
specialized structure inside cells that have characteristic chapes and functions
where is an organelle
in a cell
what does organelles do/whats it made of
what is it
functional compartment where specific processes take place and has its own enzymes
what is a centrosome
organelle
pair of centrioles and pericentriolar matric. pericentriolar matric contains 100s of tubulins-ring shaped proteins that organizing center’s for growth of mitotic spindle–important in cell division and making microtubules in nondividing cells
where is a centrosome
near nucleus
what is a centrosome made of
two centrioles(cylindrical structures)-composed of 3 microtubules in a circle pattern with pericentriolar matrix around it
what is cilia
organelle
what is cilia made of
short, hairlike projections that extend from the surface of the cell
what do cilia do
steady movement of fluid along the cell’s surface
motile projections of the cell surface
what is flagella
organelle
motile projection of the cell surface
what is flagella made of
similar in structure to cilia but bigger
ex sperm cell tail
what do flagella do
move an entire cell…motile projections of the cell
what is a ribosome
site of protein synthesis
where is a ribosome
in cytoplasm or bonded to the endoplasmic reticulum to from rough ER
what is a ribosome made of
large and small subunit made in nucleous of the nucleus
what do ribosomes do
synthesize proteins for insertion into the plasma membrane or for export from the cell
free ribosomes synthesize proteins used in the cytosol
what is the endoplasmic reticulum
organelle
Rough ER-synthesizing secretory proteins and membrane molecules
smooth ER-where fatty acids and steroids are synthesized
what is the ER made of
network of folded membranes in the form of flattened sacs or tubules, extend throughout cytoplasm and connects to nuclear envelope
where is the ER
throughout the cytoplasm…1/2 the membranous surfaces in cytoplasm of cells
what is the rough er/what does it do
factory for synthesizing secretory proteins and membrane molecules
synthesizes glycoproteins and phospholipids that are transferred into cellular organisms, inserted into the plasma membrane or secreted in exocytosis
what is the rough er made of
folded membranes with the outer membrane studded with ribosomes
where is the rough er
extends from the nuclear envelope
where is the smooth er
extends from the rough er
what does the smooth er do
forms a network of membranous tissues
synthesizes fatty acids and steroids
inactivates drusg and other harmful substances
removes phosphate group from glucose-6-phosphate
stores and releases calcium(triggers muscle contraction)
what is the smooth er made of
folded membranes in the form of flattened sacs or tubules without ribosomes
what is the golgi complex
first step in the transport pathway
what is the golgi complex made of
3-20 cisterns..flattened membranous sacs with bulging edges that are piled on eachother
what does the golgi complex do
more extensive in cells that secrete proteins
modifies, sorts, packages and transports proteins received from the rough er
what are lysosomes
membrane enclosed vesicles that may have up to 60 digestive enzymes
sacs of powerful digestive enzymes-digests old and worn out cell structures
lysosomes are made of
enzymes…and carrier proteins (lysosomal membrane) allows the final products of digestion
what do lysosomes do
breaks down molecules
digests old and worn out cells
what are peroxisomes
vesicle containing oxidative enzymes
what do peroxisomes do
detoxifies harmful substances
ex. hydrogen peroxide and free radicals
enzyme that can destroy superoxide
what are peroxisomes made of
oxidases-enzymes that oxidize (remove hydrogen atoms)
what is a proteasome
tiny barrel shaped structure
what is a proteasome made of
proteases (barrel structures) and enzymes that cut proteins
what do proteasomes do
degrades unneeded, damaged, or faulty proteins by cutting it into small peptides
if proteasomes fail to degrade abnormal proteins
diseases can occur such as Parkinson’s and Alzheimer’s
what is a Mitochondria
site of the most ATP production
what are mitochondrias made of
two membranes
outer mitochondrial membrane is smooth
inner mitochondrial membrane is arranged in cristae(folds)
there is a large central fluid filled cavity enclosed by the inner membrane and cristae called mitochondrial matrix
inner and outer membrane, cristae, matrix
where is the mitochondria
in the cytoplasm in the nucleus
stages of mitosis
prophase-nuclear envelope starts to disintegrate, assembly of mitotic spindle
metaphase-chromosomes line up in the middle…each cells gets a functioning genome
anaphase-splits sister chromatids and are pulled to the pole by the fibres
telophase- chromosomes clusrter at the poles and nuclear memrbane forms around it
cytokinesis-division of the 2 daughter cells
before entering mitosis-in interphase where it grows
mitosis-asexual reproduction, replaces damaged tissues
what is mitosis
dividing a cell into two daughter cells that are identical to the parent cell
what is interphase
resting phase between successive mitotic divisions of a cell
where it spends most of the time and grows
steps of interphase
G1 the cell grows larger and organelles are copied
S phase- cell synthesizes a complete copy of dna in its nucleus
G2 cell grows more, makes proteins and organelles and reorganizes its contents to prep for mitosis
transport mechanisms
all molecules possess kinetic energy and are in constant motion
Passive
Active
what is passive transport
transport from high conc to low conc
NO ENERGY
-diffusion
-simple diffusion
-facilitated diffusion
- osmosis
what is diffusion
moves from an area of high conc to low conc
important for every cell in the body
what happens at equilibrium
net diffusion stops but random movements continue
types of diffusion
simple diffusion
facilitated diffusion
what does simple diffusion do
unassisted movement of solute through a differently permeable membrane
what does simple diffusion allow to move across the membrane
oxygen, CO2, Nitrogen gas, fatty acids, steroids, fat soluble vitamins (a,d,e,k), water and urea
what is facilitated diffusion
molecules are assisted in ordered to be transported across plasma membrane
bigger molecules-use carrier protein
smaller molecules-cross through water-filled channels
where is filtration
capillary walls and requires pressure
what is osmosis
net movement of water molecules through a selectively permeable membrane
movement of water due to the conc gradient of nonpenetrating solutes
what is isotonic solution
cells have normal size and shape. this is ideal
in intravenous solutions
what is hypertonic solution
cells lose water and shrink
shrivel and shrink
shrinkage is called crenation
used for ppl who have cerebral edema
what is hypotonic solution
hippo
absorbs water and then bursts
rupture is called hemolysis
used for ppl who are dehydrated
types of active processes
active transport
vesicular transport
what is an active process
a cell that uses energy (atp) to move substances across plasma membrane
what is active transport
movement against concentration gradient
requires carrier proteins to move substances
what does active transport do
transport substances across the membrane against a concentration gradient
most important pump-na/k pump…expels Na ions and brings in K ions…this pump acts as an enzyme to split ATP
what is vesicular transport
movement of large particles
types of vesicular transport
endocytosis -into the cell
exocytosis- out of the cell
what is endocytosis
when substances brought into the cell are surrounded by a bit of the plasma membrane and it buds off inside to form a vesicle containing the ingested substances
types of endocytosis
phagocytosis
bulk phase endocytosis
what is phagocytosis
cell eating, large solid particles (whole bacteria, aged or dead cells) are taken in by the cell
two or more pseudopods surround and bind to form a vesicle-phagosome that enters cytoplasm
consumes solid particles
what does phagocytosis do
vital defense mechanism that protects the body from disease
what is bulk phase endocytosis
cell drinking…consumes liquid (doplets of extracellualr fluid)
the plasma membrane folds inward to form a vesicle then it pinches off of the plasma mebrane and enters cytosol
what is exocytosis
secretion of materials from a cell
out of cell
exocytosis is important in
secretory cells-liberates digestive enzymes, hormones, mucus and other secretions
nerve cells-neurotransmitters are released this way
why is the balance between endocytosis and exocytsosis important?
keeps surface area of a cell’s plasma membrane constant
