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Mechanisms for chromosome movement Animation

By: HWC, Views: 3660

At mitotic metaphase, the fully-formed spindle is composed of many microtubules that extend from the poles. Some of these, the kinetochore microtubules, are attached to the kinetochores of each chromosome. Kinetochores are located at the centromeres. At anaphase, sister chromatids separate and...

Bond types - Atomic structure and basis of bonds

By: HWC, Views: 7056

• Chemical bonds are fundamental to the structure and function of many types of molecules, such as proteins, carbohydrates, lipids, nucleic acids, gases, salts and water. ■ These molecules are composed of atoms that are held together by three different types of bonds. • The three types ...

Protein digestion - stomach & small intestine

By: HWC, Views: 6099

• Protein digestion occurs in the stomach and small intestine. • The stomach enzyme pepsin initiates the process. • Pancreatic and intestinal brush border enzymes complete the digestive process. • In the stomach, pepsin is created from pepsinogen in the presence of pH-lowering hyd...

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...

Male Reproductive System - The gonadotropin releasing hormone

By: HWC, Views: 7387

• Hormonal mechanisms that influence male reproductive function involve endocrine tissues contained in the: • Hypothalamus of the brain. • Anterior pituitary. • Testes. • In the hypothalamus, certain neurosecretory cells secrete gonadotropin- releasing hormone (GnRH). • GnRH ...

Sperm Formation

By: HWC, Views: 4623

Spermatogenesis takes place inside the seminiferous tubules. Diploid spermatogonia located near the outer edge of the tubule divide mitotically to form primary spermatocytes. The first meiotic division produces secondary spermatocytes with a haploid number of duplicated chromosomes. T...

Hershey Chase Experiments

By: HWC, Views: 3823

Hershey and Chase knew that T4 bacteriophages consist of proteins and DNA. They asked which viral component must enter a bacterial cell to infect it: DNA or protein? They grew viruses with either radioactive sulfur, which labels the viral protein, or radioactive phosphorus, which labels DNA. ...

Effect of blood chemistry - stimuli, hyperventilation response and hypoventilation response

By: HWC, Views: 6440

• Respiratory rate is effected by changes in: • Blood pH. • Blood Pco2. • Blood P02. • Chemoreceptors in the central and peripheral nervous systems closely monitor the Fr, CO2 and 02 levels in blood. • Changes in frequency of impulses from Chemoreceptors affect respiratory r...

Olfaction. or the sense of smell

By: HWC, Views: 4045

Do you ever wonder how you can distinguish thousands of different odors? Olfaction. or the sense of smell, is used by all mammals to navigate, find food, and even find mates. We have millions of olfactory receptors for smelling in our nose. These receptor neurons bind water-soluble or volatil...