Ch1 Flashcards
(24 cards)
What is the first principle of cell theory?
All organisms are made up of cells.
What is the fundamental unit of life?
The cell is the fundamental unit of life.
Where do all cells arise from?
All cells arise from pre-existing cells.
What is a nucleoid?
The nucleoid is found in prokaryotic organisms and contains concentrated genetic material.
What are organelles?
Organelles divide the cell content into smaller areas specialized for different functions.
What defines all cells?
All cells are defined by the cell membrane.
What is the major component of the cell membrane?
Phospholipids are the major component of the cell membrane.
What does it mean for a molecule to be amphipathic?
Amphipathic molecules have both hydrophobic and hydrophilic regions.
What is the hydrophilic part of a phospholipid?
The phosphate head group is hydrophilic.
What are the characteristics of fatty acid tails?
Fatty acid tails are hydrophobic and non-polar.
What is a micelle?
A micelle is a shape formed by the phosphate head groups.
What are liposomes?
Liposomes are spherical bilayer structures formed by phospholipids in water at pH 7.
Why are bilayers effective cell membranes?
Bilayers are effective cell membranes because they form closed structures that prevent exposure of hydrophobic chains to water.
This organization explains why membranes are self-healing.
What does membrane fluidity refer to?
Membrane fluidity refers to the ability of membrane lipids to move within the plane of the membrane.
What factors affect membrane fluidity?
The length of carbon to carbon double bonds and the number of double bonds in fatty acid tails affect membrane fluidity.
What is cholesterol’s role in cell membranes?
Cholesterol is a major component of animal cell membranes and is amphipathic.
What are transporters in cell membranes?
Transporters are membrane proteins that move ions or molecules across the membrane.
What is the function of receptors in cell membranes?
Receptors allow the cell to receive signals from the environment.
What role do enzymes play in cell membranes?
Enzymes catalyze chemical reactions.
What is the function of anchors in cell membranes?
Anchors help maintain the shape and structure of the cell by attaching to proteins.
What are integral membrane proteins?
Integral membrane proteins are permanently associated with cell membranes and cannot be separated without destroying the membrane.
What are peripheral membrane proteins?
Peripheral membrane proteins are temporarily associated with the lipid bilayer and can be easily separated.
What are transmembrane proteins?
Transmembrane proteins span the entire lipid bilayer.
What is the fluid mosaic model?
The fluid mosaic model describes the lipid layer as a structure where molecules move laterally and is a mixture of different types of molecules.
