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Membrane transport proteins - pores, gated channels and pumps

By: HWC, Views: 6726

• a Three different types of membrane ion transport proteins are required to produce and carry electrical signals: • Pores • Gated channels • Na+/ K+ pump • Pores are always open and allow the diffusion of Na+ and K+ ions across the membrane, down their concentration gradients...

Inflammatory response Animation

By: HWC, Views: 3169

Any tissue damage or bacterial invasion can bring about inflammation. The inflammatory response can be triggered by an invasion of bacteria, or by a cut or other physical damage to cells. Chemicals, such as histamine, released by the bacteria or damaged cells. accumulate in the tissue. Thes...

How proteins function? How do proteins work?

By: HWC, Views: 6258

How proteins function is really about how proteins "do work" in cells. How do proteins work? Let's start thinking about protein function by looking at something important to you: your hair. Keratin is a structural protein that is composed of 2 intertwined or helical strands. Keratin is also f...

Facilitated Diffusion - Glucose transport

By: HWC, Views: 6885

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...

Buffers definition and the role of buffer in the body

By: HWC, Views: 6789

■ Too many H+ break hydrogen bonds and a protein comes apart. ■ Buffers react with excess H+ to protect proteins from breaking down. ■ Buffers consist of weak acid plus anions of that weak acid. This solution contains: • hydrogen ions • weak acid (H2CO3) • anions of we...

Spermatogenesis Animation

By: Administrator, Views: 9900

Spermatogenesis is the process by which haploid spermatozoa develop from germ cells in the seminiferous tubules of the testis. This process starts with the mitotic division of the stem cells located close to the basement membrane of the tubules. These cells are called spermatogonial stem cells. T...

Plant Defense Mechanisms from Pathogens

By: HWC, Views: 6081

Plants and pathogens have coevolved such that pathogens can recognize plants by the sugars, or other molecules, they produce. Plants, in turn, can recognize pathogens by the molecules they produce. The ability to recognize pathogens allows plants to activate defense systems that can prevent wides...

Muscle cell structures - actin, myosin and titin filaments

By: HWC, Views: 6762

Once the muscle cell has been excited it will contract. • A muscle action potential will trigger the release Of Ca2+ ions into the sarcoplasm. • The Ca2+ ions bind to the regulatory proteins and trigger contraction. • Within skeletal muscle cells are structures that provide the ability...

The pH scale - Strong acids and Weak acids

By: HWC, Views: 6697

The pH scale • Expresses concentration of H+. • range: 0-14. • 7 is neutral. • Less 7 is acid. • greater 7 is basic (alkaline). Strong acids - role in the body ■ In strong acids all molecules dissociate. ■ HC1 is highly acidic and found only in the stomach. • H...