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Membrane transport proteins - pores, gated channels and pumps

By: HWC, Views: 6749

• 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...

Membrane Protein and Facilitated Transport (Passive Vs Active)

By: HWC, Views: 6262

Membrane proteins are common proteins that are part of, or interact with, biological membranes. Membrane proteins fall into several broad categories depending on their location. Integral membrane proteins span the membrane, with hydrophobic amino acids interacting with the lipid bilayer and hy...

Non-polar compounds - insolubility

By: HWC, Views: 6691

• A non-polar molecule has uniform distribution of electrons. • Non-polar compounds like fatty acids in lipids have a high proportion of carbon and hydrogen. • Lipids possess no charge or partial charge. • Lipids are not attracted to water molecules. • Lipids are not soluble in...

DNA close up Animation

By: HWC, Views: 539

A section from a DNA double helix The backbone of each DNA strand consists of alternating deoxyribose sugars and phosphate groups. The two strands run in opposite directions. One runs from the 5' to 3' direction, the other in the 3' to 5' direction. Think of the deoxyribose units o...

Complement Proteins Animation

By: HWC, Views: 3473

Formation of membrane attack complexes. Complement proteins can activate when they bind to antibodies that are bound to a pathogen. Complement proteins also activate when they bind directly to bacterial surfaces. Cascading reactions yield huge numbers of different types of complement protei...

Kinetic parameters & Kinetic experiment

By: HWC, Views: 6502

Kinetics is a measure of the speed or rate of a chemical reaction. A study of kinetics allows us to determine which variables to control (temperature, reactants, catalysts) and how to vary them in order to maximize the amount of products formed and minimize the time involved. Vmax = maximum ve...

Phases of an Action Potential - Resting Potential, Threshold, Rising, Falling, & Recovery Phases

By: HWC, Views: 6099

In this tutorial, we will review the phases of an action potential measured from a small area of a neuron's membrane. The action potential can be divided into five phases: the resting potential, threshold, the rising phase, the falling phase, and the recovery phase. When the neuron is at rest,...

Endocytosis -Types and Phagocytosis

By: HWC, Views: 6683

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...

DNA Replication

By: HWC, Views: 3495

DNA replication is the process by which a double-stranded DNA molecule is copied to produce two identical DNA molecules. Replication is an essential process because, whenever a cell divides, the two new daughter cells must contain the same genetic information, or DNA, as the parent cell.