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Second Messengers in the Inositol-lipid Signaling Pathway

By: HWC, Views: 7001

Extracellular signals produce specific responses in target cells through the action of intracellular second messengers. Here, we focus on three second messengers, IP3, DAG, and Ca2+, all involved in the inositol-lipid signaling pathway. A hormone-receptor signal on the cell surface leads to the a...

Lipid catabolism ( ketogenesis and oxidation of glycerol) and Lipid anabolism (lipogenesis)

By: HWC, Views: 8029

• During excessive beta oxidation, the two-carbon fatty acid fragments are converted into acidic ketone bodies. • Ketosis, the overproduction of ketone bodies, can lead to acidosis (ketoacidosis) of the blood. • After lipolysis, glycerol is converted to pyruvic acid. • Pyruvic aci...

Complement Proteins Animation

By: HWC, Views: 4479

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...

Neural Reflex Arc Animation

By: Administrator, Views: 10929

A reflex arc is a neural pathway that controls a reflex. In vertebrates, most sensory neurons do not pass directly into the brain, but synapse in the spinal cord. This allows for faster reflex actions to occur by activating spinal motor neurons without the delay of routing signals through the bra...

Molecules, Membrane Permeability and Structure

By: HWC, Views: 7185

Organisms are not isolated system at equilibrium and need to intake nutrients and electrolytes as remove wastes. Similarly Cells within an organism must also exchange compound by passing them through membrane. The permeability of a membrane is the rate of passive diffusion of molecules th...

Lipid digestion - mouth, stomach and small intestine

By: HWC, Views: 7784

• Lipid digestion takes place primarily in the small intestine; some occurs in the mouth and stomach. • Lipases are enzymes that break down triglycerides and phospholipids. • Lingual and gastric lipases hydrolyze a small amount of triglycerides. • End products are fatty acids and...

Cellular Respiration & Glucose Mobilization (Glucose transport & Phosphorylation of Glucose)

By: HWC, Views: 7520

Glucose is completely broken down into CO2 and H2O during the process of cellular respiration, which includes 3 stages: 1) glycolysis; 2) the Krebs Cycle; and 3) the electron transport chain. Glucose enters this energy yielding pathway of cellular respiration in the first stage known as...

Simple Diffusion - gases and nonpolar compounds transport

By: HWC, Views: 8037

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 ...

Evolutionary tree of life Animation

By: HWC, Views: 1382

An evolutionary tree of life that reflects mainstream thinking about the connections among major lineages (bya = billions of years ago, mya = millions of years ago). By about 3.8 billion years ago, chemical and molecular evolution had produced the first living cells. The first major divergenc...