Plant cells Flashcards
Describe the function and the structure of the cell wall
Made of cellulose forming a sieve like network. Protects and supports each cell and the whole plant.
Describe the function and structure of the chloroplasts
Has a double membrane and is filled with a fluid called
stroma. The inner membrane is a continuous network
of flattened sacs called thylakoids. A stack of thylakoids
is called a granum (grana is plural). Grana contain
chlorophyll pigments.
Site of photosynthesis. Light energy is trapped by
the chlorophyll and used to produce carbohydrate
molecules from water and carbon dioxide.
Describe the function and structure of the vacuole
Membrane bound sac in cytoplasm that contains cell
sap.
Maintain turgor to ensure a rigid framework in the cell.
Describe the function and structure of the tonoplast
The partially permeable membrane of the vacuole. Selectively permeable to allow small molecules to pass
through.
Describe the function and structure of the amyloplast
A double membrane bound sac containing starch granules.
Responsible for the synthesis and storage of starch granules.
Describe the function and structure of the plasmodesmata
Microscopic channels which cross the cell walls of
plant cells.
Enable transport and communication between
individual plant cells.
Describe the function and structure of the pits
Pores in the cell walls of the xylem. Allow water to enter and leave xylem vessels.
Describe the function and structure of the capsule
Slippery layer outside the cell wall of some species of bacteria. Protects the cell and prevents dessication.
Describe the function and structure of the ribosomes
Smaller than ribosomes found in eukaryotic cells. They consist of two sub-units and they are not surrounded by a membrane.
Protein synthesis occurs at the ribosomes
Describe the function and structure of the nucleiod
The nucleoid (meaning nucleus-like) is the irregularly-shaped region that holds nuclear material without a nuclear membrane and where the genetic material is localized. The DNA forms one circular chromosome.
The nucleoid is the region where generic
information can be found. and controls cellular activity.
Describe the function and structure of the plasmid
Small circular loops of DNA. Plasmids carry genes that may benefit the survival of the organism.
Complimentary base pairing …
The way in which nitrogenous bases in DNA pair with each other. Adenine (A) always bonds with Thymine (T) ( or uracil (U) in mRNA) and Guanine always bond with Cytosine.
RNA …
Ribonucleic acid, a molecule with long chains of nucleotides.
