1.Cell structure Biology Flashcards
what are eukaryotic cells
plants,animals.fungal cells
what are prokaryotic cells?
bacteria
Formula for magnification
image size / real size
Characteristics of the nucleus
-Contains DNA of the cell, DNA is packed with proteins called histone proteins (ensures DNA is packed efficiently) chromatin coils to form chromosomes
-Nucleus protected by double membrane = Nuclear envelope
Nuclear envelope has inner + outer lipid bilayer to protect fragile chromatin
-Nuclear pores (holes in nuclear envelope) allows mRNA + ribosomes to travel through
Characteristics of the Nucleolus
- Contains densely packed DNA and proteins
- “dark blob” seen in microscopes
- Makes ribosomes for protein synthesis
- Contains nucleoplasm (like cytoplasm)
Where are ribosomes found in the cell?
on the endoplasmic reticulum + free floating around cell
What are ribosomes made of?
- ribosomal RNA
- Protein
Two types of RNA?
mRNA and rRNA
what does mRNA do?
messenger to get instructions from nucleus
What does rRNA do?
Ribosomal RNA builds up ribosomes
What is the cell wall made up of in a prokaryotic cell?
Murein
what is murein made of?
it is a polymer made up of polypeptides and polysaccharides
What does Pili do
Waxy capsule around the outside of the cell, allows bacteria to stick together
What are mesosomes?
They are infoldings of the prokaryotic cell
What do mesosomes do?
Increase surface area of cell , aids cell for respiration
What is the cytoskeleton
Network of fibres for shape /stability of cell. Holds organelles in place and controls cell movement
what are the three components of the cytoskeleton
- microfilaments
- microtubules
- intermediate fibres
what does the microfilaments do
responsible for cell movement + cell contraction in cytokinesis (where cytoplasm splits into two cells)
What do microtubules do
determines the shape of the cell
what do intermediate fibres do
gives strength to the cell
What are vesicles
membrane sacs that transport materials inside cell + storage
What are lysosomes
specialised form of vesicles contain hydrolytic / hydrolysing enzymes, breakdown pathogens
What is the endoplasmic reticulum
network of membranes enclosed in sacs
what are the two types of endoplasmic reticulum
rough + smooth endoplasmic reticulum
what does the smooth endoplasmic reticulum do
for lipid and carbohydrate synthesis + storage
what does the rough endoplasmic reticulum do
contains ribosomes on the surface - for protein synthesis and transport proteins
