Function Of Organelles Flashcards
Cell surface membrane
Description: the membrane found on the surface of animal cells and just inside the cell wall of other cells.it’s mainly made out of lipids and proteins.
Function: regulates the movement of substances into and out of the cell. It also has receptor molecules on it which allows it to respond to chemicals like hormones
Nucleus
Description: a large organelle surrounded by a nuclear envelope (double membrane) which contains many pores. The nucleus contains chromosomes (which are made from protein bound linear DNA) and a nucleolus.
Function: the nucleus controls the cell’s activities. DNA contains instructions to make proteins. The pores allow substances to move between the nucleus and the cytoplasm. The nucleolus makes ribosomes
Mitochondrion
Description: they’re usually oval-shaped. They have a double membrane- the inner one is folded to form structures called cristae. Inside is the matrix which contains enzyme involved in respiration.
Function: the site of aerobic respiration. Aerobic respiration produces ATP- common energy source in the cell. Mitochondria are found in large number in cells that are very active and require a lot of energy.
Chloroplast
Description: a small, flattened structure found in plant cells and algal cells. It’s surrounded by a double membrane and also membranes inside called thylakoid membranes. These membranes are stacked up in some parts of the chloroplast to form grana. Grana are linked together by lamellae which are thin flat pieces of thylakoid membrane
Function: the site where photosynthesis takes place. Some parts of photosynthesis happen in the grana and other parts happen in the stroma (a thick fluid found in chloroplasts)
Golgi apparatus
Description: a group of fluid-filled membrane-bound flattened sacs. Vesicles are often seen at the edges of the sacs
Function: it processes and packages new lipids and proteins. It also makes lysosomes
Golgi vesicle
Description: a small fluid filled sac in the cytoplasm surrounded by a membrane and produced by the Golgi apparatus
Function: stores lipids and proteins made by the Golgi made by the Golgi apparatus and transports out of the cell
Lysosome
Description: a round organelle surrounded by a membrane. Dosent have a clear internal structure. A type of Golgi vesicle.
Function: contains digestive enzymes called lysozymes. These are kept separate from the cytoplasm by the surrounding membrane, and can be used to digest invading cells or to break down worn out components of the cell.
Ribosome
Description: a very small organelle that floats free in the cytoplasm it is attached to the RER. It is made up of proteins and RNA. Not surrounded by a membrane.
Function: site where proteins are made (protein synthesis)
Rough endoplasmic reticulum (RER)
Description: a system of membranes enclosing a fluid filled space. The surface is studded with ribosomes
Function: folds and processes proteins that have been made at the ribosomes
Smooth endoplasmic reticulum (SER)
Description: similar to the RER but with NO studded ribosomes
Function: synthesises and processes lipids
Cell wall
Description: a rigid structure and surrounds cells in plants, algae and fungi. In plants and algae it’s mainly made out of cellulose whereas in fungi it’s made of chitin.
Function: supports cells and prevents them from changing shape
Cell vacuole
Description: a membrane bound organelle found in the cytoplasm. It contains cell sap (a weak solution of sugar and salts). The surrounding membrane is called the tonoplast
Function: helps to maintain pressure inside the cell and keep the cell rigid. This stops the plant wilting. It’s also involved in the isolation of unwanted chemicals inside the cell.
