what is a prokaryotic cell?
cells that do not have a nucleus
what are some example of prokaryotic organisms?
what is a eukaryotic cell?
cells that have a nucleus
what are some examples of eukaryotic organisms?
protist, animals, plants, fungi, algae
what is cytosol?
intercellular fluid of the cytoplasm (made up mostly of water) which is the site of metabolic pathways and polypeptide synthesis
what is the plasma membrane?
a thin membrane around the cytoplasm of a cell
what is a cell wall?
rigid structure surrounding the cell, used to support the cell
where is the cell wall located in eukaryotic cells?
outside the plasma membrane
what is the cell wall made up of in plants?
what is the cell wall made up of in fungi?
what are ribsomes?
"lumps" of ribosomal rna and proteins
how many subunits does ribosomes have?
two (a large subunit and a small subunit); non-covalently bound to each other
what are ribsomes used for?
the synthesis of proteins
where are ribosomes found in eukaryotic cells?
in the cytosol or on the rough endoplasmic reticulum
what are membrane-bound organelles?
organelles made up of membranes
what are the membrane bound organelles found in euakryotic cells?
nucleus, chromatin, nucleolus, endomplasmic reticulum, vessicles, golgi apparatis
what is a nucleus?
contains chromosomes and functions as an information storage and processing center
what is the nuclear envelope?
A double membrane that surrounds the nucleus in the cell
what are nuclear pore complexes?
pores on the nuclear envelope that allows rna and proteins to go in and out of the nucleus
what are chromatin?
long strands of DNA and protein found in the eukaryotic cell nucleus; condense to form chromosomes
what is chromatin supported by?
the nuclear matrix
what is the nucleolus?
where rna molecules found in ribosomes are synthesized
where is the nucleolus found?
inside the nucleus
what is the endomembrane system?
membrane sacks and tubes that make proteins and lipids
what are the components of the endomembrane system?
rough endoplasmic reticulum and smooth endoplasmic reticulum
where is the endoplasmic reticulum located?
attached to the nuclear envelope
what is the rough endoplasmic reticulum?
flat sacks, studded with ribosomes
what is the rough endoplasmic reticulum involved in?
the synthesis of secreted proteins and sorting
what is the smooth endoplasmic reticulum?
tubular, not flat sacks, that contain no ribosomes
what is the smooth endoplasmic reticulum involved in?
synthesizing of lipids, manufactoring site for phospholipids used in the plasma membrane, and detoxification
what are vessicles?
membrane-bound sphere that encloses materials to be transported
where do vessicles transport materials?
form the endoplasmic reticulum to the golgi apparatus, then to the plasma membrane and other organelles
what is the golgi apparatus?
looks like a stack of pancakes used for modifying proteins, sorting, and secretion of lipids and proteins
what does the golgi apparatus consist of?
what is cisternae?
flattened, membraneous sacs within the endoplasmic reticulum and golgi apparatus
were do vessicles fuse to on the golgi apparatus?
the cis side; the side closest to the rough endoplasmic reticulum
where to vessicles bud off the golgi apparatus?
the trans side; the side oriented toward the plasma membrane
what are vacuoles?
large, membrane bound sacks
what does the central vacuole do in plant cells?
maintains water pressure and is used as a storage compartment
what does the contractile vacuole do in freshwater protists?
continually expel water
what are lysosomes?
an organelle containing digestive enzymes and has an acidic pH inside
how are lysosomes formed?
by budding off the golgi apparatus
what are the functions of lysosomes?
fuse with phagocytic vessicles and autophagy
what is autophagy?
digest worm out organelles "eating itself"
what is an example of autophagy?
what are some examples of energy-related organelles?
mitochondria and chloroplast
what is mitochondria?
powerhouse of the cell, organelle that is the site of ATP (energy) production
what is mitochondria composed of?
a double membrane (inner and outer)
what is the inner membrane of mitochondria?
is folded extensively into cristae and contains enzymes involved in cellular respiration which produces ATP
mitochondria has what kind of dna molecule?
single, circular dna
what is chloroplast?
an organelle found in plant and algae cells where photosynthesis occurs
what is chloroplast composed of?
a double membrane, thylakoids, and stroma
what are thylakoids?
pancake shaped sacks in chloroplast where photosynthesis takes place
what is stroma?
The fluid of the chloroplast surrounding the thylakoid membrane
chloroplast has what kind of dna?
single, circular dna molecules
what is the cytoskeleton?
a microscopic network of actin filaments and microtubules in the cytoplasm of many living cells that gives the cell shape and cell movement
what are microfilaments?
fine, threadlike proteins made of actin found in the cell's cytoskeleton
what is actin?
used for supporting cells and changing the cells shape and sliding filaments
what are intermediate filaments?
part of the cytoskeleton that reinforces the cell and nuclear membrane and holds organelles in place
what are microtubules?
hollow tubes of tubulin used to support the cell and as "tracks" for transporting vesicles
what is cilia?
short, numerous, and hair-like structures found on the outside of some cells that move protists and fluids around
what is flagella?
long, whip-like projections used for swimming
how many flagella can one cell have?
one or very few flagella
what is the structure of cilia and flagella?
surrounded by the cell membrane and has doublets of microtubules
how many doublets do cilia and flagella have?
9 doublets around the outside and a single pair on the inside (9+2 arrangement)
what are the external features of a prokaryotic cell?
cell coverings, cell wall, capsule, flagella, and pilli
what are cell walls made up of in prokaryotic cells?
peptidoglycans (polysaccharides and peptides)
where is the capsule located?
on the outside of the cell wall
what is the capsule made of?
glycolipids (carbohydrates and lipids)
what is the function of flagella in prokaryotic cells?
spin around and pull the cell through fluid
how did flagella in prokaryotic cells evolve?
evolved independently from eukaryotic flagella
what is pilli?
hair-like structures, that look like cilia, on a prokaryotic cell
what is pilli used for?
attachment to environment and exchange of plasmids
what are the internal features of a prokaryotic cell?
nucleoid, ribosomes, plasmids, cytoskeleton, and few membrane-bound organelles
what is a nucleoid?
has a singular, circular chromosome, but is not a true nucleous because it does not have a nucleolus membrane
what are plasmids?
small, circular extra chromosomal dna molecules that can be copied and passed on to other prokaryotic cells
what kind of genes do plasmids contain?
non-essential genes; genes that allow survival in stressful environments
what is an example of a photosynthetic membrane-bound organelle?
what are magnet-sensing membrane-bound organelles in prokaryotic cells?
little crystals of magnitude inside a vacuole that function as a compass needle to help cells swim in a directed way
where is the cytockeleton in prokaryotic cells?
limited to the outside near the cell membrane of the cell
what are three differences between a prokaryotic cell and eukaryotic cell?
eukaryotic cells have a nucleus and prokaryotic cells do not. eukaryotic have many membrane-bound organelles and cytoskeleton and prokarytoic have very few membrane-bound organelles and cytoskeleton. eukaryotic cell walls are made of cellulose and chitin and prokaryotic cells have peptidoglycan in the cell wall
how did the endomembrane system develop in eukaryotic organelles?
through the enfolding of the cell membrane
how did mitochondria develop in euakryotic cells?
from purple bacteria
how did chloroplast develop in eukaryotic organelles?
from photosynthetic bacteria
what is the endosymbiosis theory?
the theory that eukaryotic cells evolved from the fusion/engulfment of two or more prokaryotic cells creating mitochondria and chloroplast
how was mitochondria developed according to the endosymbosis theory?
energy producing bacteria was engulfed by a larger cell and came to reside within that cells, eventually envolving into euakryotic cells
how was chloroplast evolved according to the endosymbosis theory?
photsynthetic bacteria may have come to live within early eukaryotic cells, leading to the evolution of chloroplasts
what is some evidence for the endosymbiosis theory?
single, circular chromosome is in chloroplast, both have a double membrane, size of both are about the size of bacteria, both can divide by binary fission
what is binary fission?
a form of asexual reproduction in single-celled organisms by which one cell divides into two cells of the same size by pinching in half and becoming two cells
what is the plasma membrane used for?
movement of substances into and out of the cell and cell signaling