Structure And Function Of Plasma Membranes Flashcards
Defines the cell, outlines the borders and determines the nature of its interaction with its environment
Plasma membrane
This model describes the plasma membranes structure as a mosaic of components and gives the membrane a fluid character
Fluid mosaic model
A molecule consisting of glycerol, two fatty acids and a phosphate-linked head group
Phospholipid
Consists of four fused carbon rings
Cholesterol
Carbohydrates on the exterior of a membrane attached to a protein is called
Glycoproteins
Carbohydrates on the exterior of a membrane attached to lipids is called
Glycolipids
Water hating molecules and tend to be non polar
Hydrophobic
Water loving molecules
Hydrophilic
Is “dual loving” and can be (-) or (+) as well as uncharged or non polar
Amphiphilic
Integrate completely into the membrane structure and interact with the phospholipid bilayers hydrophobic region
Intergral proteins
These proteins are on the membranes exterior and interior surfaces and is attached to either a integral protein or phospholipid
Peripheral protein
Third major plasma membrane component
Carbohydrates
Where is the phospholipid located
Main membrane fabric
Where is the cholesterol located
Attached between phospholipids and between the two phospholipid layers
Where are integral proteins located
Embedded within the phospholipid layers
Where are peripheral proteins located
On the phospholipid bilayers inner or outer surface(not embedded within the phospholipids)
Where are carbohydrates located
Generally attached to proteins on the outside membrane layer
This process decides if a substance can pass through the membrane or not
Selectively permeable
This process transports substances along the concentration gradient and does not require energy
Passive transport
This process transports substances against the concentration gradient and requires additional input of energy such as ATP
Active transport
Plasma membranes are…
Amphiphilic
True or false: polar substances can pass freely through the membrane
False because they have a charge meaning they require extra help to enter the membrane
This is a passive process of transport and expends no energy
Diffusion
What are some factors that affect the diffusion rate
Extent of the concentration gradient, mass of molecules diffusing, temperature, solvent density, solubility, surface area and distance travelled
What is something that can affect high blood pressure
Appearance of protein in the urine
This process diffuses materials across the plasma membrane with the help of membrane proteins
Facilitated transport
The integral proteins involved with facilitated transport
Transport proteins
These proteins have hydrophilic domains exposed to the intracellular and extracellular fluids
Channel proteins
Channel proteins that allow water to pass through the membrane at a high rate
Aquaporins
These proteins can be open at all times or “gated” which controls the channels opening
Channel proteins
This protein binds a substance and thus triggers a change of its own shape, moving the bound molecule from the cells outside to its interior depending on the gradient. These are also found embedded in the plasma membrane
Carrier proteins
The movement of water through a semipermeable membrane according to the waters concentration gradient across the membrane and is proportional to the solutes concentration
Osmosis
Moves from an area of high concentration to a low concentration
Water
An extracellular solution that can change a cells volume by affecting osmosis
Tonicity
A solutions total solute concentration
Osmolarity
3 terms to relate to the cells osmolarity to the extracellular fluids osmolarity that contains the cells
Hypotonic, isotonic and hypertonic
The extracellular fluid has lower osmolarity than the fluid inside the cell , and water enters the cell
Hypotonic
Extracellular fluid has a higher osmolarity than the cells cytoplasm therefore contains less water
Hypertonic
The extracellular fluid has the same osmolarity as the cell meaning no movement of water in or out of the cell
Isotonic
If there is not enough osmolarity in a cell the cell will die
Yes
When the cell membrane detaches from the wall and constricts the cytoplasm
Plasmolysis
We call the combined concentration gradient and electrical charge that affects an ion..
Electrochemical gradient
What do you need to move against the concentration gradient
Energy(ATP)
What works against electrochemical gradients
Pumps
What moves ions across a membrane and creates a difference in charge and is dependent on ATP
Primary active transport
This does not require ATP this is the movement of material due to the electrochemical gradient
Secondary active transport
Carries one specific ion or molecule
Uniporter
Carries two different ions or molecules but in different directions
Antiporter
Carries two different ions or molecules
Symporter
Instrument that magnifies an object
Microscope
This microscope uses a beam of electrons instead of a beam of light
Electron microscope
This theory states that one or more cells comprise of all living things, it is the basic unit of life and new cells arise from existing cells
Cell theory
Simple single celled organism that lacks a nucleus or any membrane bound organelle
Prokaryote
This cell has a membrane bound nucleus, many membrane organelles and many rod-shaped chromosomes
Eukaryotic cell
A phospholipid bilayer embedded with proteins that separate the internal contents of the cell
Plasma membrane
Houses the cells DNA and directs the synthesis of ribosomes and proteins
Nucleus
The cells entire region between the plasma membrane and the nuclear envelope and consists of 70-80% water
Cytoplasm
Double membrane structure that constitutes the nucleus outermost portion
Nuclear envelope
Semi solid fluid inside the nucleus where the chromatin and nucleolus are
Nucleoplasm
Structures within the nucleus that are made of DNA
Chromosomes
Unwound protein chromosome complexes
Chromatin
Is the powerhouse of the cell for plant and animals and is responsible for making ATP
Mitochondria
Responsible for protein synthesis
Ribosomes
Small round organelles enclosed by single membranes that carry out oxidation reactions that break down amino and fatty acids
Peroxisomes
Membrane bound sacs that function in storage and transport
Vesicles and vacuoles
A microtubule organizing center found near the nuclei of animal cells
Centrosome
This is the cells garbage disposal
Lysosomes
Protects the plant cell
Cell wall
Plant cell organelles that carry out photosynthesis
Chloroplasts
Chloroplasts contain a green pigment which captures the light energy that carries out photosynthesis
Chlorophyll
Regulates the cells concentration of water in changing environmental conditions
Central vacuole
This organelle is the final destination where lipids and proteins go where they are sorted, packaged and tagged so that they are sent in the right place
Golgi apparatus
These destroy pathogens using hydrolytic enzymes
Lysosomes
3 types within the cytoskeleton
Microfilaments, intermediate filaments and microtubules
Network of protein fibers
Cytoskeleton
They are narrow and function in cellular movement
Microfilaments
Provide some rigidity and shape to the cell
Microfilaments
Have no role in cell movement, their function is purely structural by maintaining a cells shape and anchor the nucleus and other organelles in place
Intermediate filaments
Small hollow tubes, they help resist compression, provide a track along which vesicles can pass freely and pull replicated chromosomes to opposite ends of a dividing cell
Microtubules
Microtubules are also structural elements of…
Flagella, cilia and centrioles
Long, hair like structures that enable an entire cell to move
Flagella
Short, hair like structures that move entire cells or substances along the cells outer surface
Cilia
Holds the cells together to form a tissue and allows the cells within to communicate with each other
Extracellular matrix
Cells can also communicate using
Intercellular junctions
Watertight seal between two adjacent animal cells
Tight junction
Spot welds between adjacent epithelial cells
Desmosomes
In animal cells and allow transporting ions, nutrients and other substances that enable cells to communicate
Gap junctions
