Cell Structure 2.1.1 Flashcards
Role of the nucleus
Surrounded by a double membrane called the nuclear envelope containing pores which enables molecules to enter and leave the nucleus. Contains genetic information of the cell and the activities of the cell.
Role of the cell surface (plasma) membrane
Controls what enters and leaves the cell, it is a phospholipid bilayer, it also contains protein channels.
Role of the mitochondria
Site of aerobic respiration, releases energy for the cell’s movement.
Role of the ribosomes.
Site of protein synthesis.
Role of the cytoplasm.
Where chemical reactions occur in the cell.
Role of chromatins
Package long DNA molecules into more compact, denser structures.
Role of nucleolus
Produces and assembles the cell’s ribosomes.
Role of lysosomes.
Is a vesicle containing digestive enzymes bound by a single membrane.
Role of the centrosome matrix
Centrosomes help in cell division, they maintain the chromosome number during cell division, they also stimulate the changes in the shape of the cell membrane by phagocytosis. In mitosis it helps in organising the microtubules ensuring the centrosomes are distributed to each daughter cell.
Role of peroxisomes
Specialised for carrying out oxidative reactions using molecular oxygen.
Role of the rough endoplasmic reticulum
A series of flattened sacs enclosed by a membrane with ribosomes on the surface. RER folds and processes proteins made on the ribosomes.
Role of the smooth endoplasmic reticulum.
Is a system of membrane bound sacs. SER produces and processes lipids.
Role of the secretory vesicle
Moves molecules outside the cell through a process called exocytosis.
Role of the cilia
Help move entire cells or can move substances along the outer surface of the cell.
Role of the intermediate filaments
Provide structure and support for the cells.
Role of the micro filaments
Also provide support to cells but are smaller.
Role of the cytosol
It is involved in signal transduction between the cell membrane and the nucleus and organelles. It transports metabolites from their production site to other parts of the cell. It is important for cytokinesis, when the cell divides in mitosis.
Role of the centrioles
They are hollow cylinders containing a ring of microtubules arranged at right angles to each other. They are also involved in cell division.
Role of microvilli
Increase the surface area in order to absorb more nutrients.
Role of the microtubules
They function both to determine cell shape and in a variety of cell movements, including some forms of cell locomotion, the intracellular transport of organelles, and the separation of chromosomes during mitosis.
Role of the nuclear envelope
separates the contents of the nucleus from the cytoplasm and provides the structural framework of the nucleus. The nuclear membranes, acting as barriers that prevent the free passage of molecules between the nucleus and the cytoplasm, maintain the nucleus as a distinct biochemical compartment.
Role of the Golgi apparatus
Packages proteins into vesicles to be transported around the cells to where they’re required. Some of the proteins such as extracellular enzymes leave the cell by exocytosis.
Role of the permanent vacuole
Found in plants. A single membrane sac filled with fluid containing salts, sugars, and amino acids. The membrane around a cell vacuole is called the tonoplast. To provide support to a cell, store amino acids and sugars, and can contain pigments to attract pollinators.
Role of the cell wall
The cell wall separates the interior contents of the cell from the exterior environment. It also provides shape, support, and protection to the cell and its organelles. However, this cellular component is present exclusively in eukaryotic plants, fungi, and a few prokaryotic organisms. Made of peptidoglycan.
Role of chloroplasts
They have a double membrane and are the site of photosynthesis, they contain thylakoids which contain chlorophyll. Chlorophyll is the green pigment used in photosynthesis as it attracts the sunlight.
Role of tonoplasts
Is a membrane which surrounds the vacuole which functions to separate the vacuole from the rest of the cell.
Role of amyloplasts
An organelle found in only plant cells that produces, breaks down and stores starch.
Role of pits
Thin areas on the secondary walls of plants, they aid in the transport of minerals and water between the cells
Role of plasmodesmata
They are small channels that directly connect the cytoplasm of neighbouring plant cells.
Role of the capsule - prokaryotic
Protective slimy layer which helps the cell to retain moisture and adhere to surfaces.
Role of plasmids
Circular piece of DNA
Role of the flagellum
A tail like structure which rotates to move the cell
Role of the pili
Hair like structures which attach to other bacterial cells.
