human cellular structure Flashcards
what are the features of the cell?
-plasma membrane
-nucleus
-nucleolus
-rough endoplasmic reticulum
-smooth endoplasmic reticulum
-golgi apparatus
-mitochondria
-nuclear envelope
what does the plasma membrane do?
controls materials that move in and out of the cell
what does the nucleus do?
contains dna for protein synthesis
what does the nucleolus do?
makes ribosomes
what does the rough endoplasmic reticulum do?
contains ribosomes for protein synthesis
what does the smooth endoplasmic reticulum do?
synthesis lipids and carbohydrates
what does the golgi apparatus do?
packages proteins into membrane bound sacks called vesicles
what does the mitochondria do?
site of aerobic respiration and atp synthesis
what does the nuclear envelope do?
double membrane around nucleus that has pores to allow mrna to leave
what is the other name of the cell membrane?
fluid mosaic model
what’s the meaning of fluid in the fluid mosaic model?
the phospholipid molecules within a layer can move relative to each other
what’s the meaning of mosaic in the fluid mosaic model?
the proteins within the phospholipid layer are of different sizes and shapes and form different patterns
are cell membranes fully permeable or selectively permeable?
selectively permeable
what does selectively permeability mean?
they only allow certain molecules through
how can permeability be increased?
-temperature
-organic solvents
what molecules can move directly through the phospholipid bilayer?
-lipid soluble substances (vitamin a)
-small molecules (o2 and co2)
what molecules can’t pass through the phospholipid bilayer?
water soluble substances (glucose, ions, all polar molecules)
how do the water soluble substances move through the phospholipid bilayer?
intrinsic proteins
what is the phospholipid bilayer made of?
-phospholipids
-extrinsic proteins
-intrinsic proteins
where are extrinsic proteins found?
outer surface of the bilayer
what are the extrinsic proteins called with sugars attached?
glycoproteins
what do glycoproteins do?
hormone receptor sites
where is cholesterol found in the phospholipid bilayer?
found between the phospholipids
what’s the role of cholesterol in the phospholipid bilayer?
makes it more rigid and stable
what are the two intrinsic proteins?
-carrier proteins
-channel proteins
what is the role of carrier proteins?
allows larger plot molecules through (water-soluble sugars and amino acids)
what is the role of channel proteins?
pores lined with polar groups that allow charged ions through
what is the phospholipid bilayer made of?
-hydrophilic head
-hydrophobic tails
how can permeability be increased?
-temperature
-organic solvents
