Module 3&4: Transport of Materials Across the Cell Membrane & Cell Types Flashcards
The most acceptable cell membrane model today. First proposed by Seymour Jonathan Singer & Garth L. Nicolson in 1972 to describe the structure of cell membranes.
Fluid Mosaic Model
Who first proposed the Fluid Mosaic Model and in what year?
Seymour Jonathan Singer and Garth L. Nicolson in 1972
This is amphipathic, which means it has hydrophilic and hydrophobic ends.
phospholipid
A phospholipid is _, which means it has hydrophilic and hydrophobic ends.
amphipathic
Made up of a phosphate group, has affinity with water
hydrophilic head
Made up of fatty acids, does not have affinity with water
hydrophobic tail
Ways a phospholipid can move in bilayer
rotation
lateral diffusion - sideward
transversal diffusion - move from inner layer to outer layer or vice versa (happens the least)
What is formed between the phospholipids and acts as a fluidity buffer?
cholesterol
Two types of proteins in the phospholipid bilayer
peripheral proteins and integral proteins
Proteins that cross the bilayer
integral proteins
Proteins found only on the surface of the cell membrane
peripheral proteins
Proteins may come in the form of carrier or channel proteins that facilitate the transport of materials across the cell membrane. Hormones react with protein receptors located in the cell membrane of their target cells.
One membrane-bound protein and an enzyme called _ are needed for breaking down blood glucose.
glyceraldehyde-3-phosphate dehydrogenase
Membrane proteins with attached carbohydrate chains; on the surface of the cell; help with cell recognition and communication especially in the immune system; proteins with sugar molecules
glycoproteins
Lipids with attached carbohydrate chains; lipids with sugar molecules; maintain cell membrane stability and assist cell-to-cell interactions;
glycolipids
What does a sugar-binding protein that some glycoproteins have that help in facilitating cell-to-cell contact?
lectin
This may interfere with the person’s blood circulation and can lead to death. Or this is when red blood cells stick together.
Agglutination
Transport that does not require energy. Focus will be given to simple diffusion, facilitated diffusion, and osmosis.
Passive Transport
Molecules follow down the concentration gradient. This means that molecules move from an area of greater concentration to an area of lesser concentration. This process does not require ATP.
Diffusion
Diffusion of materials across the cell me is influenced by the molecules’ properties:
size, polarity, and change
Transport proteins are needed to move molecules from an area of greater concentration to an area of lesser concentration.
Facilitated Diffusion
Proteins that may come as carrier proteins or channel proteins.
Transport proteins
Change their shape to transfer molecules. he enclosure of the carrier proteins prevents the hydrophilic or charged molecules to interact with the nonpolar part of the cell membrane.
Carrier proteins
Create a hydrophilic path through the bilayer. Some are large, allowing some hydrophilic molecules. Some are small, allowing ions to pass through.
Channel proteins
Membrane proteins that allow ions to pass are sometimes called _.
ion channels
In _, water molecules move from an area of higher water concentration (more water molecules) to an area of lesser water concentration (fewer water molecules). This is sometimes called diffusion of water.
Osmosis
The environment of the cell may be described as ,,_ depending on the concentration of the solute.
isotonic, hypotonic, hypertonic
The solute concentration is equal to that of the cell.
Isotonic
The solute concentration is lower than that of the cell.
hypotonic
The solute concentration is higher than that of the cell.
hypertonic
Molecules move from an area of low concentration to an area of high concentration. This kind of transport requires an energy.
Active Transport
Large substances can be taken in by the cell. They gather in big groups, like in bulk packaging.
Bulk Transport
In bulk transport, large substances can be taken in by the cell through a process _.
endocytosis
The inward folding of the membrane.
Invagination
The portion of the cell membrane eventually pinches off, forming the _ which is covered by the _.
endocytic vesicle; endocytic membrane
Three basic types of endocytosis
phagocytosis, pinocytosis, receptor-mediated endocytosis
The cell, which is called a phagocyte, engulfs large solid objects, which may be in the form of large molecules or another type of organism.
This type is also called cell eating.
phagocytosis
The cell takes in small drops of extracellular fluid from the environment. Egg cells are nourished by their surroundings through _.
This is also called cell drinking.
pinocytosis
Receptors are found in the pit coated with a protein called clathrin. The pit covers the molecules when the receptors are triggered. Low-density lipoprotein is taken up by the cell through _.
receptor-mediated endocytosis
In receptor-mediated endocytosis, receptors are found in the pit coated with a protein called?
clathrin
The release of substances from the cell. Opposite of endocytosis.
Exocytosis
Five-kingdom scheme is used to classify organisms
Plantae
Fungi
Animalia
Protista
Monera
Only kingdom that are prokaryotes
Monera
Cells without a true nucleus, but they have a nucleoid. (from the Greek words pro, which means “before”, and karyon, which means “nut or kernel”).
Prokaryotes
Size of prokaryotes
1-5 micrometers (um) only
Some prokaryotes may also contain small, double-strands of separate DNA called _, which play a role in antibiotic resistance.
plasmids
Cell division happens through _, a type of asexual reproduction that produces two identical cells. Exocytosis and endocytosis are not observed in prokaryotes.
binary fission
Cells that have a true nucleus, which are bound by the nuclear membrane. (from the Greek words eu, which means “true” and karyon which means “nut or kernel”).
Eukaryotes
