gen bio 1 exam 2 Flashcards
what do hydrophilic heads on the phospholipid bilayer of the cell membrane allow
allows cells to be in contact with aqueous
solutions → Enables biological processes and biochemical reactions to occur
ribosome’s main function
protein synthesis
ribosome structure
dot-like, mRNA wedged between its 2 subunits
cell wall (prokaryotes)
composed of peptidoglycan, wraps around the cell membrane
- extra layer of protection, helps maintain
cell’s shape and prevents dehydration
capsule
outside of cell wall, composed of polysaccharides; enables cell to attach to surfaces
flagella
whiplike structure; used for locomotion
pili
tubelike structures outside the capsule; for exchanging genetic material during conjugation
fimbriae
thread like structures outside the capsule used to attach to a host cell or a surface
what is the purpose of bacterial conjugation via pili
to gain antibiotic resistance
what is the process of bacterial conjugation
- pilus of donor cell attaches to recipient cell
- F plasmid DNA material transfers
- donor regenerates its own plasmid
- both cells are F+
nucleus
houses the cell’s DNA and directs the synthesis of ribosomes and proteins
nuclear envelope
a barrier that separates the nucleus from the cytoplasm (inner and outer layers are composed of phospholipid bilayers)
function of nuclear envelope
Contains a variety of proteins that function in the organization of genetic material and the synthesis of proteins
nucleoplasm
semi-solid fluid inside the nucleus
nucleolus
darkly staining region within nucleus;
produces and assemble the cell’s ribosomes.
nuclear pore
holes on the nuclear envelope that allow for passage of materials in and out of nucleus
chromosomes
long DNA molecule comprising part or all of the genetic material of an organism; Has a 3d structure that is achieved by packaging proteins
chromatin
unwound versions of chromosomes
peroxisome
metabolizes waste (looks like circles)
vacuole
membrane-bound sacs that function in storage and transport
mitochondria
site of ATP production
lysosome
organelle that contains digestive enzymes; come from the Golgi apparatus
ER
interconnected membranous sacs and tubules that collectively modifies proteins and synthesizes lipids
rough ER
protein modification (e.g. folding and addition of modifications like phosphate group); has ribosomes on outer membrane
smooth ER
lipid and carbohydrate synthesis
lumen
hollow portion of the ER
Proteins that are synthesized in the rough ER are transported where
golgi apparatus
golgi apparatus
Sorts, tags, packages and distributes
proteins and lipids
golgi apparatus appearance
flattened membranous sacs
where are the cis and trans side of the golgi apparatus
Cis: side facing ER and nucleus
Trans: side facing plasma membrane
vesicle purpose
transport of materials to other parts of the cell or out of the cell
vesicle structure
structure within or outside a cell, consisting of liquid or cytoplasm enclosed by a lipid bilayer
* May contain proteins, lipids, ions and other organic
molecules
lysosome function
Break down excess or damaged cell parts
into their molecular subunits for reuse by
cell
* Destroy invading pathogens (e.g.) viruses
and bacteria.
* If cell is damaged beyond repair, lysosomes can help it to self-destruct (e.g programmed cell death, or apoptosis)
lysosome apperance
dark, almost spherical structures under the electron microscope
peroxisome function
Contains antioxidants to prevent oxidative
damage in cells
* Peroxisomes of animal cells contain catalase
catalase
an enzyme which converts hydrogen peroxide to water and oxygen
- antioxidant