Blue Book Page 11 Flashcards
(23 cards)
What is the role of cholesterol in the bilayer of the cell membrane?
Permits ion movement
What is the composition of the cell membrane?
Proteins: 55%, Lipids: 40%, Carbohydrates: 5%
What is the structure of the lipid bilayer?
Phospholipid molecules arranged in a bilayer with hydrophilic (phosphate) heads and hydrophobic (fatty acid) tails
Which type of substances pass easily through the lipid layer of the cell membrane?
Fat-soluble substances like oxygen, CO2, steroids, alcohol
How do water-soluble substances pass through the cell membrane?
Through channels or carriers
The lipid bilayer of the cell membrane is highly soluble for?
CO2
Maximum permeability of the cell membrane is to?
Water
What are aquaporins?
Water channel proteins that allow water to cross membranes faster than by diffusion
Integral proteins in the cell membrane are joined to lipids by what type of bonds?
Hydrophobic bonds
Why can O2 and CO2 diffuse through the cell membrane?
Because they are lipid-soluble
Water enters the cell by which process?
Through pores
Water absorption across the cell membrane occurs via?
Pores
Water goes from plasma to interstitial fluid by which process?
Filtration
Water from the cell enters the extracellular space via which process?
Filtration
Which organelle contains oxidases?
Peroxisome
What is the function of the rough endoplasmic reticulum (RER)?
Synthesis of proteins
What is the function of the smooth endoplasmic reticulum (SER)?
Synthesis of lipids and steroids, metabolism of calcium, and detoxification
What gives the cell basophilia?
Ribosomes
What is the function of the Golgi apparatus?
Processing, packaging, labeling, and delivery of proteins and lipids
From where do lysosomes arise?
Golgi apparatus
What is the function of lysosomes?
Degradation of worn-out organelles
What is the function of ribosomes?
Synthesis of proteins
The endoplasmic reticulum is continuous with what structure?
Nuclear membrane
