Cell structure Flashcards
How are prokaryotic cells different to a eukaryotic cell?
Prokaryotic cells have no membrane-bound organelles
all reactions occur in the cytoplasm
What is an example of a prokaryotic cell?
Bacterial cell
What extra structures do bacterial cells have?
Cell wall
Capsule
Flagella
Pili, fimbriae
How are eukaryotic cells different to a prokaryotic cell?
Have membrane-bound organelles
reactions are organised into these organelles
What are some examples of eukaryotic cells?
Animal cells
Plant cells
What is the structure of a phospholipid molecule?
Head made up of glycerol, phosphate
Tail made up of two fatty acid chains
How do phospholiids react to water? Why?
Are amphipathic - have both hydrophobic and hydrophilic parts
Hydrophilic head because is negatively charged
Hydrophobic tails because are non-polar
What arrangements do phospholipids take in water and oil?
Form a monolayer with heads pointing towards water, tails pointing towards oil
Form a bilayer with heads pointing towards water, tails pointing to each other
What is the structure of the plasma membrane?
Phospholipid bilayer
proteins embedded in the bilayer
What are the types of arrangements of proteins in the plasma membrane? What do they each mean?
Integral - in contact with the hydrophobic core of the bilayer
Peripheral - attached to inner or outer surface of bilayer
What is the glycocalyx?
The oligosaccharide and polysaccharide chains on outside of plasma membrane
What are the oligosaccharride and polysaccharide chains in the glycoclayx attached to? What does this form?
Attached to lipid
forms glycolipid
Attached to protein
forms glycoprotein
What are the functions of the plasma membrane?
Selective permeability
Exocytosis, endocytosis
Signal transduction
What is selective permeability?
Lets some molecules through it
but not others
What does the fluid mosaic model of the plasma membrane mean?
Fluid refers to the phospholipid bilayer being flexible
Mosaic refers to the proteins embedded in the phospholipid bilayer
What is the shape of rough endoplasmic reticulum?
Flat cisternae
What is attached to rough endoplasmic reticulum?
Ribosomes
What is the shape of smooth endoplasmic reticulum?
Tubular shape
Are ribosomes attached to smooth endoplasmic reticulum?
No
What are the functions of smooth endoplasmic reticulum?
Lipid synthesis
Steroid synthesis
Where is smooth endoplasmic reticulum abundant in cells?
Liver
Adrenal glands
Ovaries, testes
What is the function of ribosomes?
Protein synthesis
Where are ribosomes located in the cell? Where do the proteins they produce go?
Cytoplasm, proteins remain there
Attached to rough endoplasmic reticulum, proteins pushed into rough endoplasmic reticulum