Cells Flashcards
What is passive transport?
Passive transport is when molecules diffuse from a region of high concentration to a region of lower concentration and does not require energy.
What are the 4 primary types of passive diffusion?
Simple diffusion, facilitated diffusion, filtration, and osmosis.
What is facilitated diffusion?
Facilitated diffusion is when molecules diffuse across a cell membrane with assistance from membrane proteins and carriers.
Examples: large and charged molecule (carbohydrates, amino acids, and ions)
What is simple diffusion?
The simplest form of diffusion is simple diffusion. Molecules diffuse through a semipermeable membrane down their concentration without assistance from transporter proteins.
Examples: oxygen and carbon dioxide
What are transport proteins?
Transport proteins are proteins that move molecules across the membrane within a cell. Transport proteins aid in facilitated diffusion and active diffusion.
Examples: channel proteins, carrier proteins, and sodium potassium pumps
How do channel proteins aid facilitated diffusion?
Channel proteins can aid in facilitated diffusion of substances by forming a hydrophilic passage through the membrane through which polar and charged substance can pass.
What is active transport?
Active transport is when molecules/ions are moved against their concentration gradients from a region with lower concentration to a region with higher concentration which requires energy (ATP)
Protein physically bind to the material during active diffusion
What is endocytosis?
Endocytosis is a cellular process in which substances are brought into the cell by engulfing them in a vesicle. The materials surrounding the membrane are internalized.
Examples: fluids, proteins, and other macromolecules.
What type of transport is endocytosis? What are the two subdivision of endocytosis?
Endocytosis is a form of active transport.
Endocytosis is divided into two subdivisions, pinocytosis and phagocytosis.
What is phagocytosis?
Phagocytosis (the cell eating) is when cells engulf and digest. It is the ingestion of large particles by a large vesicle (phagosome)
Examples: destroys a virus/infected cell often used by the immune system
What is pinocytosis?
Pinocytosis (the cell drinking) is when the cell takes in fluids along with dissolved small molecules. It described the internalization of extracellular fluid and small macromolecules by a small vesicle
Example: absorption of fat droplets
What is receptor mediated endocytosis?
Receptor mediated endocytosis is when receptor proteins on the cell surface are used to capture specific, target molecules. It is a specific process for substances recognized by a cell-surface receptor. A specialized form of Pinocytosis.
Example: The ingestion of cholesterol
What is bulk transport?
Bulk transport is a mode of transport for large quantities of materials and food particles across the membrane.
Bulk transport: phagocytosis, pinocytosis, receptor-mediated endocytosis
What is Exocytosis?
Exocytosis is when cells move large materials from inside the cell to the outside of the cell using small spheres of membranes called vesicles. It is a form of active transport.
Example: secretion of proteins like enzymes
What is the purpose of active diffusion?
The main function of active transport is to pump molecules and ions across membranes against their concentration gradients. Active transport is an energy-requiring process that can transfer substances into, out of, and between cells
What type of energy does active transport use?
Active transport uses chemical energy that comes directly from ATP hydrolysis. Adenosine Triphosphate.
How can you increase diffusion rate?
By increasing temperature, surface area, change in shape of molecules, and changes in concentration.
What is the sodium potassium pump?
The sodium potassium pump is a carrier protein and a form of active diffusion and pumps three sodium ion into the cell and two potassium ions outside of the cell against their concentration gradient.
What is the difference between the two types of transport proteins (channel proteins and carrier proteins?)
Channel proteins only transport ions and molecules down the concentration gradient, which does not require any energy. Carrier proteins transport substances both down and against the concentration gradient
What does ATP stand for? What is it made of?
Adenosine triphosphate. The structure of ATP is a nucleoside triphosphate, consisting of a nitrogenous base (adenine), a ribose sugar, and three serially bonded phosphate groups.
What type of molecules are transported in active transport?
Active transport is usually associated with accumulating high concentrations of molecules that the cell needs, such as ions, glucose and amino acids
How can water be transported in facilitated diffusion?
Through an aquaporin which is a integral protein/channel protein in the phospholipid bilayer
What is an example of a carrier protein used in facilitated diffusion?
Permeases is found in the chloroplast and transports molecules down their concentration gradient and into the cell by changing shapes.
