Search results for: 'proteins'

Watch Later 3:50

By: HWC, Views: 7119

First step: strands are separated • Helicase unwinds the DNA double helix at the replication fork • SSBs coat the single strands to prevent reannealing • Polymerase attaches nucleotide at 3' end • Synthesis is in 5' to 3' direction DNA Polymerase: • Only extends nucleic ac...

Watch Later 1:25

Glomerubular filtrate rate -pressures that affect GFR and net filtration pressure

By: HWC, Views: 8172

• The glomerular filtration rate is the amount of filtrate formed per minute within the renal corpuscle. • Once the filtrate is formed it moves down the tubule. • The production and movement of filtrate depends on three pressures: I. Glomerular blood hydrostatic pressure (GBHP) is pre...

Watch Later 1:43

Protein digestion - stomach & small intestine

By: HWC, Views: 7193

• 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...

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Types of disease resistance: innate defenses & immunity

By: HWC, Views: 7962

Our immune system protects us and helps fight off disease. Microorganisms, small microscopic organisms, and viruses are everywhere. Ever thought about how many are on that door you just opened? Many microbes and viruses can cause disease and are termed pathogens. Plants and animals have what i...

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Primary and secondary response to infection

By: HWC, Views: 7470

• 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...

Watch Later 1:32

Hydrogen bonds vs. Ionic bond

By: HWC, Views: 6508

The slight positive charge of a hydrogen atom in a water molecule can attract an atom with a slight negative charge, such as the nitrogen in a molecule of ammonia. This forms a hydrogen bond between the two atoms. Hydrogen bonds join the two strands of a DNA molecule. Although hydrogen bo...

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Mitochondrial Structure & ETC Protein Complexes (Protein Complexes and Electron Transport)

By: HWC, Views: 7336

The energy carrying molecules, NADH and FADH2, that were generated in glycolysis and the Krebs cycle, now are processed in the mitochondria where their high energy electrons are deposited in an electron chain complex located in the inner mitochondrial membranes. These high-energy electrons now dr...

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Nucleic acid digestion - brush border enzymes, end products & transport mechanism

By: HWC, Views: 7508

• Further digestion occurs at the microvilli (brush border) of the epithelial cells of the villi in the small intestine. • Two brush border enzymes complete nucleic acid digestion: • Phosphatases, which catalyze the cleavage of a phosphate to form a nucleoside (nitrogenous base and pent...

Watch Later 1:43

Mechanisms for chromosome movement Animation

By: HWC, Views: 4726

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...

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