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Type of Transport - Active and Passive Processes

By: HWC, Views: 9643

Active transport moves materials from lower to a higher concentration, while passive transport moves materials from higher to lower concentration. Active transport requires energy to proceed, while passive transport does not require the input of extra energy to occur. Transport processes that ...

Simple Diffusion - gases and nonpolar compounds transport

By: HWC, Views: 9721

Gases and some molecules can diffuse through the phospholipid bilayer because they are small or non-polar. Oxygen gas. Carbon dioxide gas. Lipid based hormones. Plasma membranes are selectively permeable: The lipid bilayer is always permeable to small, nonpolar, uncharged molecules ...

Simple Diffusion - Ion transport

By: HWC, Views: 9394

In the process of diffusion, a substance tends to move from an area of high concentration to an area of low concentration until its concentration becomes equal throughout a space. Ions must diffuse through membrane pores or gated channels. Pores are always open. More pores allow more ions...

Facilitated Diffusion - Glucose transport

By: HWC, Views: 9619

Transmembrane proteins help solutes that are too polar or too highly charged move through the lipid bilayer The processes involved are: Channel mediated facilitated diffusion Carrier mediated facilitated diffusion In facilitated diffusion, molecules only move with the aid of a protein i...

Osmosis - water transport

By: HWC, Views: 9493

Osmosis is the flow of water down its concentration gradient, across a semi-permeable membrane. Osmosis is an example of diffusion, which is when molecules tend to distribute themselves evenly in a space. what is a semi-permeable membrane? It is a membrane or barrier that allows some molec...

Osmosis - Isotonic, Hypotonic, and Hypertonic​ Solutions

By: HWC, Views: 9473

Isotonic: Equal Water moves in and out of the cell at an equal rate. The cell remains unchanged. Hypotonic: "hypo" hippo Water moves into the cell, making it swell and get fat (like a hippo). Eventually the cell can rupture and burst (aka lyse). Hypertonic: "like a raisin" Water leaves...

Primary Active Transport - electrochemical gradient and ion transport / water movement

By: HWC, Views: 9511

Energy derived from ATP changes the shape of a transporter protein which pumps a substance across a plasma membrane against its concentration gradient An electrochemical gradient is a gradient of electrochemical potential, usually for an ion that can move across a membrane. The gradient consis...

Secondary Active Transport

By: HWC, Views: 9944

Energy stored (in a hydrogen or sodium concentration gradient) is used to drive other substances against their own concentration gradients Secondary active transport, is transport of molecules across the cell membrane utilizing energy in other forms than ATP. In many cells, antiporters mov...

Endocytosis -Types and Phagocytosis

By: HWC, Views: 9420

Endocytosis is the process by which a substance is brought inside a cell without having to pass through the cell membrane. It is the opposite of endocytosis, the process by which substances exit the cell without having to pass through the cell membrane. Exocytosis – membrane-enclosed secret...