Chapter 5 Flashcards
Fluid mosaic model
The cell membrane is a mosaic of Phospholipids Cholesterol Proteins Carbohydrates
A cell membrane can
Receive external signals
Give cellular responses
Glycocalyx
Nametag of cells that help show that a certain cell belong to the human body
Carbohydrates in the cell membrane such as the glycoprotein and glycolipids
Proteins in the plasma membrane
Receptors
Enzymes
Adhesion
Transport
Integra proteins have _ or more regions that are hydrophobic
1
Hydrophobic amino acids determine which parts of a protein is hydrophobic
True
Knowing the structure of the protein helps see where it inserts into the
Membrane
Ligosaccharide carbohydrates
Exterior of the plasma membrane
Bound to proteins or lipids
Help bind other things
Factors that affect fluidity of a membrane
- phospholipid type
- temperature
- cholesterol
A membrane with _ fatty acids is more fluid
Unsaturated
Cold temperatures_ molecules
Compress
Making them more rigid
Cholesterol
Fluidity buffer
-keeps membrane from getting too firm or too fluid
Cholesterol in high concentration makes a
Lipid raft
Plasma membrane is asymmetrical
Inner surface is different than outer surface
Interior proteins bind
Parts of the cytoskeleton to the membrane
Exterior proteins bind
Extracellular matrix
Glucoproteins
Bind to substances cells need to import
All cells keep an imbalance of Na and K ions between interior and exterior environment
More Na outside
More K inside
Factors that affect diffision
- Concentration gradients
- Mass of molecules
- temperature
- Solvent density
- solubility
- surface area
- Distance
- Pressure
Carrier proteins are
Specific to a substance
Method in which carrier proteins work
- bind
- Change shape
- Carry substance to the other side
Many carrier proteins allow movement in
Either direction
One example are
Glucose transport proteins
Tonicity
How can extracellular solution can change the volume of a cell by affecting osmosis
Osmolarity
Solute concentration of a solution
Plaamolysis
Detachment of plasma memebrane
Osmoregulation
Maintaining osmotic pressure
For example in plants to keep turgor pressure
Osmotic pressure
The pressure you must put on a solvent to keep it from passing into a solution by osmosis
Osmoregulation happens in organisms that are not plants
- paramecia
- amoeba
Paramecia and amoeba use contractile vacuoles so they don’t burst
Osmoregulation
Saltwater animals are -with respect to their environment
Isotonic
Active transport
Requires ATP
Moves against the concentration gradient
Types of active transport
Primary active transport
Secondary active transport
Primary active transport
ATP provides energy
Secondary active transport
Electrochemical gradient provides energy
How is your nervous system activated
Axons cause a Na to be pumped into the cell causing it to aquire a positive charge
To deactivate this K is pumped out of the cell
To regulate K and Na levels a sodium potassium pump helps
Sodium potassium pumps pump
3 Na out
2 K in
25 % of calories power
Na K ATP pumps
3 types of pumps
Uniporter
Carries one substance
Symporter carries 2 molecules or ions in the same direction
Antiporter
Carries 2 molecules or ions in different directions
Bulk Transport is used when
The amount of molecules is too big to be transported through carrier proteins
Which characteristic promoted the utilization of lipids as the first cell memebrane
-self assembly into a simple memebrane
The endosymbiont theory is supported by everything except the fact that
Mitochondria lack ribosomes like prokaryotes
The junctions that allow heart to beat are
Gap junctions
False about the Golgi apparatus
It decreases in size when a cell increases protein production
The complex of proteins and DNA in a nondividing cell is
Chromatin
An immune system cell called the plasma cell produces thousands of antibodies (proteins) per second for release into the body. What type of intracellular structure is common within the cell
Rough endoplasmic reticulum
Contractile vacuoles
Prevent the cell from bursting
Skin cells are fastened into sheets by
Anchoring junctions
Animal cells have
Lysosomes and centrioles
