Organelles Flashcards
What is the mitochondria?
an oval shaped organelle with a double membrane
what does the mitochondria do?
It is involved in aerobic respiration
It is responsible for production of ATP molecules which carry energy
What does the outer membrane do in a mitochondria?
It controls the flow of materials in and out of the mitochondria
What is a golgi apparatus?
An organelle that contains membrane bound, flattened sacs with vesicles on the outside
What does the golgi apparatus do?
processes, modifies and packages proteins and lipid into vesicles
What is a vesicle?
a small, fluid-filled sac in the cytoplasm surrounded by a membrane
What does a vesicle do?
It transports substances in and out of the cell via the cell surface membrane where fusion occurs
During fusion, the contents of the vesicle are released outside the membrane
What does a nucleus, overall, do?
controls cell activity
contains genetic material
What is a nucleus?
A large, organelle surrounded by a nuclear envelope with nuclear pores and contains a nucleolus and chromatin
What does the nucleolus do?
synthesises ribosomes
What do the nuclear pores do?
allows large molecules like mRNA to exit the nucleus
What is chromatin made up of?
proteins and DNA
What does chromatin do?
controls cell activity
What is the nuclear envelope?
the double membrane
What does the nuclear envelope do?
controls the entry and exit of materials from the nucleus
What is a cell wall?
A rigid, structure that surrounds plant cells mainly made of cellulose
What is the function of a cell wall?
It supports plant cells
What is a ribosome?
A very small organelle that either floats free in the cytoplasm or is attached to the RER.
What is the function of ribosomes?
the site where proteins are made
What is a plasma membrane?
It is the membrane found on the surface of animal cells and just inside the cell wall of plant cells and prokayotic cells
Function of a cell surface membrane
It regulates the movement of substances in and out of the cell
It has receptor molecules which allow it to respond to chemicals such as hormones
`What is a lysosome?
A round organelle surrounded by a membrane, with no clear internal structure
Contains digestive enzymes
They are kept separate from the cytoplasm by the membrane
Function of a lysosme?
It is used to digest invading cells or to break down worn out components of the cell
What is an SER?
They are sheet like membranes throughout the cell
Function of SER
Synthesises and processes and lipids and cholesterol
What is an RER?
sheet like membranes throughout the cell enclosing a fluid filled space surface
is covered in ribosomes
Function of an RER
synthesises and processes proteins
What organelles may be found in plant cells but not in animal cells?
cell wall with plasmodesmata
vacuole
chloroplasts
What are cristae?
extensions of the inner membrane
What does the cristae do?
increases the surface area for the attachment of enzymes
What is the matrix?
the matrix is found inside the mitochondria and contains, lipids, trace DNA along with enzymes for respiration
What is a chloroplast?
a small, flattened structure with stacks of membrane
it is surrounded by a double membrane
What is the chloroplast for?
It is where photosynthesis takes place
some happens in the grana (stacked up membranes) some happens in the stroma (a thick fluid found in chloroplasts)
What are centrioles?
small, hollow cylinders made from microtubules
found in all animal cells but only some plant cells
What do centrioles do?
they are involved in the separation of chromosomes during cell division
What are cillia?
they are small hair-like structures found on the surface membrane of some animal cells
What is the cillia made up of?
it has an outer membrane and a ring of nine pairs of microtubules with two microtubules in the centre
What does the cillia do?
the microtubules in the cillia allow the cilia to move and this movement is used by the cell to move substances along the cell surface
What is the flagellum?
They are like cillia but longer.
They stick out from the cell surface and are surrounded by the plasma membrane
They have 9 microtubules in a ring and two in the centre
What does the flagellum do?
the microtubules contract to make the flagellum move and the flagella are used as outbouard motors to propel cells forward.
