Cells alive 1- cell structure and function Flashcards
What are the main constituents of a cell?
Nucleus
nuclear pore
nuclear envelope
Mitochondria
Endoplasmic reticulum
Ribosomes
Peroxisomes
Cytoplasm
Actin filaments
Intermediate filaments
Microtubules
Lysosome
Plasma membrane
Golgi apparatus
what does it mean by phospholipids being amphipathic?
has hydrophobic and hydrophilic parts
Which part of phospholipid is hydrophilic and why?
Phosphate group - polar as negatively charged due to O-
What are the main differences between bacterial, animal and plant cells?
- bacterial cells are prokaryotic so have no nucleus or membrane-bound organelles
- bacteria and plant cells have cell walls when animal cells do not
How are phospholipids arranged in cell membranes?
Spontaneously form bilayers.
Hydrophilic heads are on each side of membrane, with all hydrophobic tails on the inside, separating inside of cell from outside
What are some properties of cell membrane?
dynamic and fluid
if there is more saturated phospholipid tails what does this mean for the membrane?
what happens if they are unsaturated?
saturated
= fewer gaps = more rigid = less effective membrane
unsaturated
= more gaps between molecules = more fluid = less effective
What are the different components in the phospholipid bilayer?
- cholesterol
- phospholipid
- protein
What is the function of cholesterol in the cell membrane?
Gives membrane structure and rigidity, it helps modify how fluid the membrane is with different temperatures
What would a saturated membrane be like without cholesterol if it was very cold?
Too rigid
Not as fluid/flexible
May break
What would a saturated membrane be like without cholesterol if it was very hot?
Too fluid/flexible
Won’t hold shape
What 2 regions do cell membrane proteins have? Why
Hydrophilic and hydrophobic areas, so they can be embedded in membrane but also sticking out of both sides
