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Mutations and translation

By: HWC, Views: 5895

A mutation, which may arise during replication and/or recombination, is a permanent change in the nucleotide sequence of DNA. Damaged DNA can be mutated either by substitution, deletion or insertion of base pairs. Mutations, for the most part, are harmless except when they lead to cell death or t...

Molecules, Membrane Permeability and Structure

By: HWC, Views: 8816

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...

Brain Anatomy Animation (Part 1 of 2)

By: Administrator, Views: 12742

The human brain is the central organ of the human nervous system, and with the spinal cord makes up the central nervous system. The brain consists of the cerebrum, the brainstem and the cerebellum. It controls most of the activities of the body, processing, integrating, and coordinating the infor...

Role of the respiratory system - effect of altered ventilation rates

By: HWC, Views: 9893

• The respiratory system regulates blood pH by controlling the amount of carbon dioxide removed from the blood. • Near systemic cells, carbon dioxide forms bicarbonate ions in the blood. H+ ions are also released, thereby decreasing blood pH. • At the alveolar capillaries, bicarbonate io...

Lipid digestion - mouth, stomach and small intestine

By: HWC, Views: 9400

• 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...

Retina

By: Administrator, Views: 12620

Eye Composed of special anatomical structures that work together to facilitate sight: Cornea Pupil Lens Vitreous body Light stimulates sensory receptors (rods and cones) in the retina or innermost layer of the eye. Vision is made possible through the coordinated actions of nerves that co...

Conduction of action potentials

By: HWC, Views: 9472

• Action potentials must be rapidly conducted over long distances in order for the nervous system to communicate with other cells. • Propagation of an action potential uses processes similar to those that generate the potential at the trigger zone. • a When a graded potential reaches ...

Types of antimicrobial substances (interferons & complement protein)

By: HWC, Views: 9383

• Found in blood and interstitial fluids. • Discourage microbial growth. • Include interferon and complement proteins. • Produced and released by virus-infected lymphocytes. • Enter new cells and inhibit viral replication. • Act against a large variety of viruses (non-speci...

Hormonal regulation of pregnancy - weeks 17 through 38

By: HWC, Views: 9554

• Estrogens increase uterine blood flow, maintaining the endometrium during pregnancy. • High levels of estrogen and progesterone inhibit the synthesis of milk. Progesterone inhibits myometrial contractions of the uterus to prevent premature birth. • Relaxin inhibits myometrial contract...