biology - module 2 cell structure Flashcards
what is a plasma cell membrane and it’s function
the membrane found on the surface of animal cells and inside the cell wall of plant cells and prokaryotic cells .it’s made of mainly lipids and protein
function: has receptor molecules which allow it to respond to chemicals like hormones
cell wall description and function
a rigid structure that surrounds plant cells, made out of carb: cellulose
function: supports plant cell
Nucleus description
large organelle surrounded y nuclear envelope ( double membrane) which contains pores , nucleus contains chromatin ( made from DNA and proteins) and contains a nucleolus
Nucleus function
controls cell’s activities by controlling transcription of DNA which contains instructions to make proteins , the Nucleolus is where ribosomes are made
lysosome description and function
round organelle surrounded by a membrane with no clear internal structure
function: contains digestive enzymes to digest invading cells or to break down worn out components of the cell - they are usually kept separate from the cytoplasm by the surrounding membrane
Ribosome description and function
a small organelle that floats free in cytoplasm or attached to the RER, made up of proteins and RNA
function: where proteins are made
RER
system of membranes enclosing a fluid filled space - covered in ribosomes
Function: folds and processes proteins that have been made at the ribosome
SER
Similar to RER but no ribosomes
Function: to synthesise and processes lipids
Vesicle function and description
a small fluid filled sac in the cytoplasm surrounded by a membrane
function: Transports substances in and out of the cell ( via plasma membrane) and between organelles
some are formed at the RER/SER , Golgi apparatus while some form at the cell surface
Golgi apparatus function and description
a group of membrane bound flattened fluid filled sacs , vesicles are often found at the edges of the sacs
Function: processes and packages new proteins and lipids and also makes lysosomes
Mitochondria function and description
Oval shaped , has a double membrane , the inner membrane is folded to form structures called cristae , inside the cristae where the matrix is which contains enzymes involved in respiration
Chloroplasts func and description
a small flattened structures found in plant cells, often have a double membrane also inside the cell they contain membranes called thylakoid membranes which are stacked up in the chloroplast called Grana - linked by a lamellae - thin flat pieces of the membrane
Function: where photosynthesis takes place , most happens in the grana while some takes place in the the stroma ( thick fluid found in chloroplast)
Centriole func and description
small hollow cylinders made of microtubes found in animal ells but some plant cells
function: involved with separation of chromosomes during cell division
Cilia func and description
hair like structures found on the surface membrane of some animal cells . in the cross section they have an outer membrane and a ring of nine pairs of protein microtubules inside has two microtubules in the middle
Function: the microtubules allow the cilia to move so the cell can move substances along the cell surface
Flagella
on Eukaryotic cells, like cilia but longer , stick out on cell’s surface and are surrounded by the plasma membrane inside are like cilia: 2 microtubes in the middle and 9 pairs of protein microtubules surrounding it
Function: contract to make flagella move - propel cell forwards
