What are the two different types of cells?
eukaryotic (more complex, with nucleus and membrane bound organelles), prokaryotic (simpler, smaller and without nucleus)
-All cells contain it
-is a selective barrier. in small things, non polar, not charged
-cell increases in size, volume grows more proportionately than are (plasma) hence why cells split before getting too large
Why do organisms generally have many cells, not smaller cells?
-cells increase, volume grows way more than area, so cell splits before it gets too large
What is the fluid inside a cell?
What are chromosomes?
Carry genes in form of DNA
What are ribosomes
organelle that makes proteins
What are some differences between prokaryotic and eukaryotic cells?
1) location of DNA - prokaryotes dont have nucleus
2) other membrane bound organelles - prokaryotes dont
3) complexity - eukaryotes more complex
4) size - eukaryotes tend to be larger
5) Presence of flagella/fimbriae - prokaryotes have, eukaryotes dont
7) prokaryotes don't have mitochondria either
fimbrae - movement on the surface of some
nucleoid - region where cell's DNA is, but not enclosed
ribosomes - make proteins
flagella - for movement
What is the nucleoid?
In prokaryotes, it is where the cell's DNA is stored, but it is NOT an enclosed organelle.
What are some differences bw an animal and a plant cell?
Animal - has centriole, lysosomes, ECM
Plant - has central vacuole, chloroplasts, amyloplast (starch grain), cell wall, chlorophyll, photosynthesizes
Cell Membrane is also known as
What are membranes made of usually?
A double layer of phospholipids, as well as other lipids (like cholesterol) and proteins
What is the primary purpose of a cell membrane?
To control movement in and out of the cell, define cell from outside space
Which organelle has a single layer?
Peroxisome (although not part of the endomembrane system)
-part of the endomembrane system
-contains most of genes
-has double membrane itself
-has pores that allow mRNA in and out of the nucleus
-pore complex lines each pore and regulates entrance and exit of proteins
What does a pore complex do in the nucleus?
lines each pore and regulates entrance and exit of proteins
Where else are genes located aside from nucleus? Why?
-mitochondria and chloroplasts
-theory suggests that they used to be their own organisms and were trapped in the cell.
Structure of the nucleus
What is the nuclear lamina?
Netlike array of protein iflaments that maintain the shape of the nucleus in the nuclear side of the envelope.
What is the nuclear matrix?
Network of fibers extending throughout the nuclear interior
DNA is loacted in
chromosomes, made up of a material called chromatin (proteins and DNA)
what is the nucleolus?
Nucleolus synthesizes rRNA (proteins leaving cytoplasm are assembled with this rRNA and go into making ribosomal units)
-can have to or more nucleoli
-made of ribosomal RNA from nucleolus and protein, it carries out protien synthesis
-both in prokaryotic and eukaryotic
-interprets instructions in mRNA, links amino acids with peptide bonds
What are the two types of ribosomes?
Free and bound. They are structurally the same thing.
Free ribosomes are
suspended in the cytosol
proteins from here function in cytosol
attached to ER (in rough ER)
make proteins bound for outside of cell
Notice that there is a space b/w small subunit and large subunit. This is where the ribosome pieces together a protein.
Cells that specialize in protein secretion have a high proportion of what?
Bound ribosomes. Bound ribosomes make proteins bound for membranes or inside organelles.
Transport vesicles budd off ER and other endomembrane organelles. It fuses with their membrane.
-walks along tracks of microtubules (think kinesin feet)
What is the golgi Apparatus
Products of the ER are modified and sometimes sotred here
-manufacturing, warehousing, sorting, shipping
-vesicles from ER enter in cis face
-travel through ER, are modified
-leave in own vesicles for transport in trans phase
How are lysosomes made?
-Golgi collects lysosomal enzymes in their tips
-Then buds off in its own membrane to be lysosomes
-cells specialized for secretion/detox have lots of Golgis/lysosomes
What happens in the golgi?
-packing, sorting, modification of phospholipids, proteins
-many polsyaccharides are made here
-storage of lysosome enzymes
membranous sac of hydrolytic enzymes
-can break open, causes auto digestion
-aids in phagocytosis (engulfs small organisms or food particles for food)
-mergers with food vacuoles at eats them!
What is an example of a lysosomal cell?
White blod cells (macrophages)
What is autophagy?
The cell recycles its own organic material. Lysosome will surround it and eat it, allowing its building blocks to be something else.
how are food vacuoles formed?
How do vacuoles manage water?
In paramecium, for example, there are contractile vacuoles to get rid of excess water
What is the central vacuoles?
In plants, holds food, water, waste, starch
-also helps to hold up the cell (it's HUGE)
solution inside vacuole is sap and not cytosol
What are the organelles in the endomembrane system?
What is the ER made out of?
-made of rough ER, smooth er
-made from tubules and sacs called cisternair
What do rough ER do?
-Rough ER has ribosomes attached
-these ribosomes are where protein syntehsis takes place
-Rough ER has glycosylation - addition of carbs to protein
-transport vesicles bud from rough ER
What do smooth ER do?
-outer surface doesn't lack ribosomes
-detoxifies drugs and poison
-stores calcium ions in muscle cells
What are the compartments called in ER?
Why does tolerance to drugs increase in the cell?
Drinking proliferates lysosomes, peroxisomes and smooth ER, allowing the body to detox faster, increasing its tolerance
structure of ER
what are peroxisomes
transfers hydrogen from various substrates to oxygen, producing hydrogen peroxide, but then coverts it to water
found in liver cells that detox
can multiple by splitting into two
what do peroxisomes do in seeds?
Has glyoxysomes in fat storing tissue of plant seeds that convrets fatty acids to sugar
What are chloroplasts
only in plant cells, source of photosynthesis
Plant cells contain which photosynthesis pigment?
What is the structure of a chlorplast?
outside is outer membrane
In the stroma (flui), there are granums of thylakoids
-also ribosomes and DNA in there
-inside of thylakoid is the lumen
How does photosyntehsis work?
Light passes through membrane, strikes granum
light energy in granum converted to food
Structure of a chlorplast
site of metabolic activity, creates ATP
extracts energy from food (catabolism)
Structure of mitochondria
outside layer smooth
inbetween is intermembrane space
inside membrane layer folded into layers of cristae
Cristae contain matrix
Free ribosomes and DNA are conatined here
Structure of a mitochondria
network of fibers extending through cytoplasm for support, motility and regulation
Motor proteins interact with cytoskeleton for cell motility (think kinesin!!)
What are the three types of microtubules in order or largest diameter to smalles?
2) intermediate filaments
Main functions: cell motility, maintenance of cell shape, chorosome movements in cell division (division spindle forms here), organelle movements
Structure-hollow tubes made from tubulin dimers (globular protein)
Cilia and flagella are made out of which cytoskeleton type?
What is the difference between cilia and flagella
Cilia - usualy has many, but shorter and they beat like oars. Can also be used for senseing what's going on ouside cell
Flagella, one or a few, longer, undulating motion that generates movement
Microtubles are made out of:
Tubulin protein dimers - alpha tubulin and beta tubulin. They grow by adding subunits (polymerization). they are HOLLOW
they are organized in centrosomes
What do vesicles move along?
Using ATP, motor protein snaps onto microtubule and "walks" vesicle o destination.
What are centrioles?
used for cell division in animal cells, grows out of centrosomes. Division spindle grows out of the centrioles.
Which is the thickest cytoskeleton type?
Main functions: maintenance of cell shape, changes in cell shape, muscle contraction, cell motility, cell division (cleavage formation), muscle contraction, cytoplasmic streaming
Structure-globular protein actin.
Pseudopods are created from which cytoskeleton type?
function: cell shape, anchorage of nucleus and other organelles, formation of nuclear lamina
-from fibrous proteins of the kinetin family
-is used for more permanent structures
-fixes position of certain organelles
reinforce cells, allow connection and communication between cells.
-plant cell wall
Plant cell walls
-made from microfibrils of cellulose
-primary cell wall (young plant cell, thin and flexible)
-middle lamella (b/w primary walls of adjacent cells, have pectins)
-secondary cell - matures and stops growing, plant cell strengthens its walls
in animal cells, has:
-Glycoproteins (proteins with glycogen) - fibers outside cells
-collagen fibers embedded in a network for proteoglycans (glycogen with proteins)
-fibronectin (spec glycoprotein) binds to recepter proteins called integrins bilt into paslma membrane
structure of a proteoglycan complex
Tissue, organ, organ system organization. Jnctions help to keep specificity and function.
Plant cell intercllular junction
-channels between plant cells
-allows passage of water, small solute, some proteins and some RNA to pass
Animal cell connections are called (3)
What is a tight jnction
water proof connection. Fluids can not leak between cells, they are forced to move through targeted cell membrane
neighboring animal cell pressed very tightly against each other
for structural strength
they rivet together and fasten cells into strong sheets
helped by intermediate filaments
desomosomes anchor into intermediate filaments IN cell
are channels tha tallow exchange of materials between cells (cytoplasmic channels)
What color does chlorophyll absorb? Reflect?
Absorbs red and blue; reflects green.