Cell Structure Flashcards
(38 cards)
What is the structure of the cell surface membrane?
- 7nm
- phospholipid bilayer
- partially permeable
What are the functions of the cell surface membrane?
- control exchange of material
- protect cell organelles
What is the structure of the nucleus?
- double membrane
- 5 - 10 μm
- nuclear envelope
- nuclear pores
- nucleolus
- DNA
- chromatin/chromosomes
What are the functions of the nucleus?
- DNA replication
- RNA replication
- nuclear division
- exchange of mRNA, ribosomes, proteins through nuclear pores
What is the structure of the rough endoplasmic reticulum?
- single membrane
- continuous with nuclear envelope
- covered in ribosomes
- cisternae
What are the functions of the rough endoplasmic reticulum?
- protein modification/transport
- break off and form golgi body
What is the structure of the smooth endoplasmic reticulum?
- single membrane
- smooth surface
- cisternae
What are the functions of the smooth endoplasmic reticulum?
- lipid/steroid/hormone synthesis
What is the structure of the golgi apparatus?
- cisternae
- golgi body
- golgi vesicles
- single membrane
What are the functions of the golgi apparatus?
- packing/modifying/organising proteins
- synthesis of glycoproteins/glycolipids
- secretion of materials out of cell
- exocytosis
- makes lysosomes
What is the structure of the mitochondria?
- double membrane
- 1 μm
- inner membrane folded into cristae
- intermembrane space
- outer membrane contains porins
- matrix
- proteins/ATP/ADP on cristae and in matrix
- circular DNA
- 70s ribosomes
What are the functions of the mitochondria?
- carry out aerobic respiration by:
- link reaction, kreb’s cycle, ETC
- self-replicating
What is the structure of the ribosomes?
- 20 nm
- no membrane
- rRNA
- protein
- two subunits
What are the functions of the ribosomes?
- protein synthesis
What is the structure of the lysosomes?
- single membrane
- 0.5 μm
- filled with hydrolytic enzymes
What are the functions of the lysosomes?
- digestion of old cells
- digestion of old organelles
- digestion of bacteria
- sent outside cell
What is the structure of the microtubules?
- alpha/beta tubulin
- 25 nm
- dimers form protofilaments
- 13 protofilaments join
- arranged throughout cell to form cytoskeleton
- no membrane
What are the functions of the microtubules?
- provides structure and support
- intracellular transport
- contract and relax
- endocytosis
- spindle fibres during nuclear division
What is the structure of the centrioles?
- 9 triplets of microtubules
- arranged in a cylinder
- right angles to each other
- form centrosome region
What are the functions of the centrioles?
- move to opposite poles during mitosis
- spindle fibres protrude from centrioles
- MTOCs for formation of microtubules
What is the structure of the chloroplasts?
- double membrane
- 3 - 10 μm
- chlorophyll
- thylakoid membranes throughout
- grana (stacked discs)
- 70s ribosomes
- circular DNA
- stroma
- starch grains
What are the functions of the chloroplasts?
- photosynthesis
- chlorophyll absorbs light energy
- make ATP
- self-replicating
- food store
What is the structure of the cell wall?
- freely permeable
- cellulose fibres
- tensile strength
- lignin
What are the functions of the cell wall
- maintains pressure gradient
- gives support to cell
- gives shape to cell
