Transcript Structure and function of cell components

Structure and function of
cell components
(i) Carbohydrates
(ii) Lipids
(iii) Proteins
(iv) Nucleic Acids
(v) Membranes
(vi) Cytoskeleton
Structure of cytoskeleton
Cytoskeleton is found in all eukaryote cells
It is anchored in the cell membrane via membrane
proteins
It is composed of 3 types of fibre
microfilaments
Microtubules
Found in all eukaryote cells
Hollow tubes made of the protein tubulin
Radiate from the MTOC (microtubule organising
centre), stretch to plasma membrane
MTOC changes length of microtubule by
assembling and disassembly ends
Microtubules can be assembled and
disassembled rapidly
Components of microtubules become spindle
fibres during cell division
Microtubules cont….
Function
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Provide structural support by resisting
compression
Have a role in organelle movement
Separate chromatids during cell division
Components of cilia, flagella and centrioles
Microfilaments
Made of actin protein
Present throughout the cell, but most common
just inside the plasma membrane
Readily assembled and disassembled
Function
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Involved in cell membrane movements e.g.
Endocytosis / Phagocytosis
Give cell shape
Are part of the contractile ring that forms the two
daughter cells during cytokinesis of animal cells
Intermediate filaments
Mostly made of keratin proteins
Not found in all cells
Probably permanent (cannot be
assembled and disassembled) although
cells may be able to regulate length
Function
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Very stable tough fibres providing cell support
Abundant in areas of a cell subject to
mechanical stress
Learning Activities
Read and take notes from DART pg (5860)
Scholar 5.3
Look back at the role of MTOCs and
spindle fibres in cell division (cell cycle
notes)
Create a list of cytoskeleton functions and
remember it
Advanced Higher Questions