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Secondary and tertiary levels of protein structure Animation

By: HWC, Views: 568

Amino acid sequence dictates a protein's final shape. The presence of certain amino acids favors a pattern of hydrogen bonding that causes part of the polypeptide chain to coil and twist into an alpha helix. The presence of other amino acids enables hydrogen bonding between strand like re...

Phases of the ovarian cycle

By: HWC, Views: 7039

• The ovarian cycle is a monthly sequence of events, consisting of three phases: • Preovulatory • Ovulatory • Post ovulatory Preovulatory phase • prior to ovulation: Primary follicles develop into secondary follicles. • Follicular cells surrounding the primary oocyte In...

Secondary Active Transport

By: HWC, Views: 7195

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...

Rh blood type and complications during pregnancy & Fertilization

By: HWC, Views: 4097

Complications can arise if an Rh- woman is impregnated by an Rh+ man. The fetus maybe Rh+. During childbirth, some of the fetal Rh+ cells may leak into the maternal bloodstream. The woman's immune system views the Rh+ as foreign and makes antibodies against it. If the woman becomes pr...

Primary and secondary response to infection

By: HWC, Views: 6402

• Pathogens enter the body by penetrating the non-specific barriers in the skin and mucus membranes. • Pathogens first encounter macrophages and natural killer cells that carry out phagocytosis and cytolysis respectively. • A pathogen's first encounter with the immune system can promo...

Summary of female reproductive cycle days 1-28

By: HWC, Views: 7102

■ The first five days of the cycle include the menstrual phase. ■ Progesterone and estrogen levels are low. ■ Menses occurs. ■ GnRH pulses more frequently promoting FSH and LH levels to rise. ■ Primary follicles are stimulated to develop. ■ Days five through thirteen consist o...

Protein Structure - Primary, Secondary, Tertiary and Quaternary

By: HWC, Views: 6657

A protein's first order structure, or primary structure, begins with the amino acid sequence of the polypeptide chain. The 20 different amino acids can be arranged in an infinite number of sequences. For example, the hormone insulin, which regulates the uptake of glucose from the blood into ce...

Carbohydrate digestion (brush border enzymes, end products) & Carb absorption (fructose, galactose)

By: HWC, Views: 6708

• Carbohydrate digestion concludes in microvilli of the small intestine, in brush border epithelial cells. Carbohydrate digestion -brush border enzymes • Four brush-border enzymes are involved: • Alpha-dextrinase breaks down alpha-dextrin chains by removing glucose units. • Sucras...

Energy Flow - Trophic Levels and Food

By: HWC, Views: 6228

All of these relationships between different species are founded on one thing: energy. Organisms get food in order to get energy, which is used by the organism for growth, maintaining health, and reproduction. We can classify the members of a community according to how they obtain food. Produc...