Eukaryotic Cells Flashcards
What is the job of the nucleolus?
It is an area in the nucleus responsible for producing ribosomes. It is made of proteins and RNA, which is used to produce rRNA (ribosomal) and combined with proteins to form ribosomes.
What is the job of a mitochondria?
Mitochondria are the site of the final stages of respiration, where the energy stored in molecules is made available to use by the cell by producing ATP. Very active cells contain a lot of mitochondria.
What is the structure of mitochondria?
Mitochondria have a double membrane, the inner membrane is highly folded to form cristae and the fluid inside is called the matrix.
The cristae contains enzymes used in aerobic respiration. Mitochondria also contain a small amount of DNA, so they can produce their own enzymes and reproduce themselves.
Vesicles
Vesicles are membranous sacs that have storage and transport roles, and consist simply of a single membrane with fluid inside. They are used to transport materials inside the cell.
Lysosomes
Lysosomes are specialised vesicles that contain hydrolytic enzymes, and are involved in breaking down waste materials in cells including old organelles and pathogens. They also play a role in programmed cell death.
What is the cytoskeleton?
The cytoskeleton is a network of fibres necessary for the shape and stability of the cell, it hold organelles in place and controls cell and organelle movement.
What are the three components of the cytoskeleton?
Microfilaments: formed from the protein actin. Responsible for cell movement and cell contraction during cytokinesis.
Microtubules: made of globular tubulin proteins that form scaffold-like structure that determines the shape of the cell. They also help with the movement of organelles. Spindle fibres in mitosis are microtubules.
Intermediate fibres: give mechanical strength to cells.
