Cell Physiology -Topic 1 Slides Flashcards
What is the smallest unit capable of carrying out the functions of life?
The cell
What is the cell to living organisms?
The structural and functional unit
What are some things that the cell does for organisms?
Obtaining nutrients, converting nutrients to energy like ATP, communicating, reproducing, synthesizing proteins which are necessary for cell structure and growth
What are Cell membranes are integral for?
Cell function
What do Intracellular membranes do?
Form the boundaries of organelles
What is movement of ions and small molecules across membrane barriers mediated and regulated by?
Transport proteins (channels and transporters
How many cells are there in the body?
30-60 trillion cells in the body
What is Intercellular space?
The space between two cells
What do all Membranes consist of?
Double layer of lipid molecules with embedded proteins
What is the head of the membrane made of?
Phospolipids
What is the tail of the membrane made of?
Fatty acid chains
Which part of the membrane is Polar?
The Phospholipid head
What part of the membrane is nonpolar?
The fatty acid chains
What does Amphipathic mean?
Have both hydrophilic and hydrophobic regions
Why don’t phospholipids form Micelles?
Because their tails are too bulky
How do kinks in the fatty acid chain affect the membrane?
They affect its ability to pack closely together in the membrane
What are all steroids made from?
Cholesterol
What is the structure of cholesterol?
3 six carbon rings and 1 five carbon ring
What makes Cholesterol have a hydrophobic side?
The carbon hydrogen side chain
What is the polarization of cholesterol?
It is Amphipathic
What makes cholesterol amphipathic?
Its carbon hydrogen side chain and its alcohol group
Where are Globular proteins located?
Float on the phospholipids of the cell membrane
What does the Lipid bilayer allow for in terms of movement?
Gives fluidity and elasticity to the membrane
Where are carbohydrates that are found in the membrane usually present?
Attached to proteins or lipids
What does Mobility of globular proteins in the membrane arise from?
Fluidity of the lipid by layer
What are the two types of proteins in the membrane?
Integral and Peripheral membrane proteins
In what ways can the membrane proteins move?
They can move laterally and change their topographic distribution within the membrane
Where are Integral membrane proteins located?
They are stuck either partially in the plasma membrane or completely span the bilayer
Where are Peripheral membrane proteins located?
They lie above the plane of the membrane and do not permeate the membrane
How can movement of cellular proteins be restricted?
They can be restricted if they are attached to other components of the membrane or other components inside or outside the cell
When is the rate of movement of phospholipids higher?
If the chain of fatty acids is shorter and they are doubled
What does a shorter chain of fatty acids mean?
There is less interaction between the tails of adjacent phospholipids
Where is the cytoskeleton located?
Inside the cytoplasm
What is the Cytoskeleton made of?
Different protein filaments that attach to each other and to parts of the plasma mem
How does cholesterol affect the membrane?
Cholesterol packs in between the phospholipid molecules and interacts with hydrocarbon chains of the tails restricting the later moment of phospholipids and making it less fluid
How does Cholesterol affect the membrane at low temperatures?
It prevents fatty acid tails from crystallizing
How does Cholesterol affect the membrane at higher temperatures?
It prevents phospholipids from moving around too much
How can the Phospholipids vary?
They have the nitrogen containing chemical group that can change
What does asymmetry in the cell membrane support?
The different functional differences of inner and outer sides of membranes
