Bio Ch 4 Flashcards
who was robert hooke
discovered the cell in 1665
known as the renaissance man of the 17th century
who developed the cell theory
Theodor Schwann and Matthias Schleiden
what is the cell theory
- all living organisms consist of one of more cell
- some cells are unicellular, so cells are the fundamental unit of life
- new cells come from pre-existing cells by cell division
- cells must show all the properties of life
- all cells are basically similar in chemical and structural composition
what are the 3 types of microscopes
- compound light 2. dissecting 3. electron
what characterizes prokaryotes
- single cell
- bacteria
- no nucleus
- contains DNA, ribosomes, cytoplasm, cell wall, and cell membrane
- smaller than plant or animal cell
what characterizes eukaryotic cells
- multicellular
- animal, plant, protists, and fungi
- contain cell membrane, DNA, ribosomes, and membrane-bound organelles
which organelles help with genetic control
nucleus and ribosomes
which organelles help with metabolism
ER, golgi, lysosomes, vacuoles, peroxisomes
which organelles help with energy processing
mitochondria (all) and chloroplasts (plant)
which organelles help with structural support, movement, and communication
cytoskeleton, plasma membrane, cell wall
what do both animal and plant cells have
mitochondria, golgi, rough and smooth ER, nucleus, cytoplasm, ribosomes
what is unique to animal cells compared to plant cells
no cell wall, small or no vacuole, no chloroplasts, flagella
what is unique to plant cells compared to animal cells
cell wall, large vacuole, chloroplasts, flagella only in something
what is the function of the plasma membrane
forms a flexible boundary between the living cells and its surroundings
how does the form of plasma membrane help its function
its super thin, which allows it to regulate the flow of material into and out of the cell
what is the function of the central vacuole
only found in plants, it stores water and a variety of chemicals
what are the parts of the nucleus
nuclear envelope, nucleolus, chromatin
what does the nucleus do
contains the cell’s DNA which directs all the cell’s activities and protein synthesis; it houses and copies DNA and passes it on to daughter cells in cell division, builds ribosomal subunits, transcribes DNA instructions into RNA which controls the cell’s functions
what does the chromatin in the nucleus do
it has the DNA attached to it
what does the nuclear envelope do
porous membrane that surrounds the nucleus and controls the flow of materials in and out
what does the nucleolus do
made of RNA and proteins; contains parts that make up the ribosomes
where are ribosomes made
in the nucleolus
what are ribosomes made of
clusters of proteins and nucleic acids
what do ribosomes do
carry out the commands of the nucleus; construct proteins
when are ribosomes free
when they are found in the cytoplasm
when are ribosomes bound
when they are attached to the rough ER or the nuclear envelope
what do ribosomes in the ER do
make proteins for membranes
what do ribosomes in cytoplasm do
make enzymes and other proteins
what does the endomembrane system do
uses connected membranes or vesicles to transport
what makes up the endomembrane system
ER, golgi, lysosomes, vacuoles, peroxisomes
what is the endoplasmic reticulum
network of membranes made of tubes and sacs continuous from the nuclear envelope
what is the function of smooth ER
makes lipids (oils, phospholipids, steroids like sex hormones); detoxifies harmful substances (can grow in response to some drugs to increase the rate of detoxification); stores calcium for muscle health
what does the smooth ER have that allows it to do its job
enzymes
what does rough ER do
make more ER membrane –> it makes proteins that are inserted right into the ER causing it to grow, or these proteins are transported out of the cell into transport vesicles or secreted by the cell to regulate bodily functions
how does the form of rough ER help its function
has attached ribosomes that produce proteins and enzymes that make more membrane, flattened sacs and tubes allow proteins to move throughout it and into transport vesicles
describe the journey of a secretory protein
- synthesized by the ribosome 2. threaded into the cavity of the rough ER 3. gets folded into its 3D shape 4. when the molecule is ready to leave the ER it is packaged in a transport vesicle. 5. this vesicle buds off from the ER membrane 6. the vesicle carries the protein to the golgi apparatus. 7. from there, a transport vesicle containing the finished molecule makes its way to the plasma membrane and releases its contents from the cell
what does the golgi apparatus do
Modifies, stores, and routes proteins and other substances to its destination
receives vesicles from the ER and transports, (enzymes change the chemical structure, then transport the vesicles to some place in the cell or out of the cell by exocytosis) ; releases lysosomes
Processing shipping center of the cell
how does the form of the golgi help its function
a series of flattened sacs that allows transport vesicles to pass through it and for the protein inside to be modified and finished correctly - one side serves as a receiving doc where vesicles fuse with a golgi sac and the other side gives rise to vesicles which bud off and travel to other sites
what is the function of lysosomes
break down large molecules and digest food and secretes these nutrients into cell fluids; breaks down damaged cell parts and recycles them
how does the form of lysosomes affect their function
contains digestive enzymes that allow it to break down and digest; a sac bound by a membrane that gives those enzymes an acidic environment that also protects them from the rest of the cell
what is the function of a food vacuole
helps to ingest food; works with lysosomes to break down food and store food
how does the form of a food vacuole affect its function
it is pinched off of the plasma membrane to encircle food particles when they enter the cell
what are peroxisomes
Metabolic compartments that do not originate from the endomembrane system
what do peroxisomes do
Break down fatty acids
Detoxify alcohol and other toxins
Release peroxide which immediately breaks down to become water
what do chloroplasts do
structure where light energy from the sun is converted to chemical energy; only found in plant cells
how does the form of chloroplasts determine their function
contain green disc-shaped structures called solar packs bc they convert solar energy; has internal membranes that separate the inside into compartments which helps it carry out couples, multistep processes; has inner and outer membrane, stroma, thylakoids, and geranium
what does the mitochondria do
where cellular respiration occurs; Energy is released from sugars and uses that energy to make ATP; cells use as their main energy source; Found in all eukaryotic cells, including plants and algae
how does the form of mitochondria determine its function
has 2 membranes around it, protecting the mitochondrial matrix which holds DNA, ribosomes, and enzymes that help speed up cellular respiration; the matrix has bends called cristae that increase surface area which increases the ability to make ATP, which means more energy
what are cell walls
Found in plants
Much thicker than plasma membrane
Rigid; made of cellulose
Contain plasmodesmata which allow fluids to pass from one cell to the next
what are junctions
they connect animal cells
what are the 3 types of junctions
tight (prevent leaking), anchoring (fasten cells together and allow stretching), and gap (allows fluid to pass between cells
what is the function of the cytoskeleteton
provides structural support (organelles don’t just flow freely); interacts with proteins to help the cell move
what are the 3 main parts of the cytoskeleton
microfilaments, intermediate filaments, and microtubules
what do microfilaments do
solid rods that form a network inside the cell so it can hold its shape and help it move
what do intermediate filaments do
thick strings of proteins; reinforce cell shape and hold cell parts in place; more permanently placed than microfilaments)
what do microtubules do
straight hollow tubes that support the cell and give cell parts a track to move on
what are flagella
long thin whiplike structures that contain microtubules that move like a snake allowing the cell to move.
what are cilia
moves a cell by a back and forth motion of its little microtubules
what is the cilia structure
9+2 tubule arrangement allows cilia to bend
Microtubules are wrapped in a protein called dynein
receive signals for the cell
