Eukaryotic cell structure - 2.4 (4) Flashcards
Module 2, Chapter 2, 2.4, Page 28 & 29
What are vesicles?
membranous sacs that have storage and transport roles
What do vesicles consist of?
a single membrane with fluid inside
What are vesicles used to transport?
materials inside the cell
What are lysosomes?
specialised forms of vesicles that contain hydrolytic enzymes
What are lysosomes responsible for?
breaking down waste material in cells, including old organelles
What important role do lysosomes play in the immune system?
they are responsible for breaking down pathogens ingested by phagocytic cells
What do lysosomes also have a important role in?
programmed cell death or apoptosis
Where is the cytoskeleton present throughout?
the cytoplasm of all eukaryotic cells
What is cytoskeleton as a network of fibres necessary for?
the shape and stability of a cell
What are organelles held in place by?
the cytoskeleton
What does the cytoskeleton control?
cell movement and the movement of organelles within cells
Three components of the cytoskeleton - What does the microfilaments consist of?
contractile fibres formed from the protein actin -> these are responsible for cell movement and cell contraction during cytokinesis
What is cytokinesis?
the process in which the cytoplasm of a single eukaryotic cell is divided to form two daughter cells
Three components of the cytoskeleton - What is the microtubules and what does it consist of?
globular tubulin proteins polymerise to form tubes that are used to form a scaffold-like structure that determines the shape of a cell -> they also act as tracks for the movement of organelles, including vesicles, around the cell -> spindle fibres are composed of microtubules
Three components of the cytoskeleton - What is the intermediate fibres and what do they consist of?
these fibres give mechanical strength to cells and help maintain their integrity
