Ultrastructure Of Cells Pt.2 Flashcards
What kind of cell has a primitive nucleus
Prokaryotic cell
What is the function of mitochondria
Providing the cell with ATP energy and is involved during respiration
Why is mitochondria semi-autonomous
Cause it has its own version of DNA and can divide without normal cell division
Describe mitochondria
Has a smooth outer wall & folded inner membrane that encloses a matrix that has enzymes and DNA
What is the function of ribosome
They are the site for protein synthesis
Where are ribosomes made
In the nucleolus
What happens after ribosomes have been made
They exit the nucleus and assemble in the cytoplasm to form functional ribosomes.
Some of the ribosomes are attached to the nuclear membrane or ER
What is the Endoplasmic Reticulum
A network of folded membrane called either the
ROUGH ER or SMOOTH ER
Function of ROUGH ER
Extends directly from nuclear envelope and synthesises proteins.
Proteins get processed and sorted
Function of smooth ER
Extends directly from the rough ER and detoxifies certain drugs
Synthesises fatty acids and steroids
Enzymes from smooth ER help glucose reach bloodstream and get rid of drugs e.g alcohol.
Function of golgi body
Contains 3-20 cistern and accepts synthesised proteins from the ROUGH ER to modify them into glyco and lipoproteins.
What is the function of chromatin
Compressing DNA into a compact unit so it takes up less space
Where is chromatin found
Nucleus
What do lysosomes do
Send out digestive enzymes
How is nucleus separated from cytoplasm
By its nuclear envelope
What is nuclear envelope made out of
Lipid bilayer
What are openings in the nuclear envelope called
Nuclear pores
What is the function of nuclear pores
Controlling movement of substances between cytoplasm and nucleus
What is the function of cell junctions
Connecting cells to each other
What kind of junctions are found in epithelial cells
Anchoring junctions/ Adherens Junctions
What kind of adherens junctions are there
Zonula Adheren with actin filaments
Macula adherens with intermediate filaments (desmosomes)
Function of macula adherens
connecting cells together that are mostly found in the epithelia and that need to withstand abrasion e.g. skin
What are tight junctions
Regions where 2 cells are very tightly connected, the whole perimeter of the cell mostly has this tight connection forming a tight belt. The region is called tight junction or zonula occluden
Why do tight junctions have tight connection between cells
To prevent any molecule from entering
What is a gap junction
A gap junction connects cells electrically or metabolically allowing cells to communicate directly. These junctions can open or close depending on changes in calcium and ph.
