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Primary Active Transport - electrochemical gradient and ion transport / water movement

By: HWC, Views: 6778

Energy derived from ATP changes the shape of a transporter protein which pumps a substance across a plasma membrane against its concentration gradient An electrochemical gradient is a gradient of electrochemical potential, usually for an ion that can move across a membrane. The gradient consis...

Functional zones in a mitochondrion

By: HWC, Views: 4646

A mitochondrion has a double membrane system. The outer membrane faces the cytoplasm. The inner membrane divides the organelles interior into two compartments. The enzymes that carry out the second stage reactions are in the semifluid matrix inside the inner compartment. Embedded in the ...

Exocytosis - secretion

By: HWC, Views: 6653

Exocytosis is another method of vesicular transport that moves large volumes Of fluid or chemicals out of the cell. It is a process by which a cell transports secretory products through the cytoplasm to the plasma membrane. A examples of cellular secretory products: 1. Secreted protein - enzym...

Bone Growth and Remodeling

By: HWC, Views: 6976

• After birth, bones grow in thickness and length. • Bones grow in diameter via appositional growth at the periosteum. • Epiphyseal plates enable lengthwise growth of long bones, such as the humerus, by interstitial growth. • Bone remodeling accommodates changing needs. • While th...

Normal and abnormal blood pH

By: HWC, Views: 6753

• Dissociation of the chemical substances in the body fluids can result in the production of free hydrogen ions. • The pH scale is used to measure the concentration of hydrogen ions in solution. • Normal blood pH values vary around 7.4. • When hydrogen ion concentration increases, t...

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

By: HWC, Views: 6447

• 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...

Acid-base imbalances - compensation of metabolic acidosis and alkalosis

By: HWC, Views: 6946

1. Metabolic acidosis: • Few HC03- ions are present so blood pH becomes acidic. • Compensation is increased respiratory rate and more CO2 is removed from the blood. • Blood pH returns to normal. 2. Metabolic alkalosis: • Many HC03- ions are present so blood pH becomes alkaline...

Oxygen transport - methods and oxyhemoglobin

By: HWC, Views: 6448

• The blood is the medium used for gas transport throughout the body. • Oxygen is only available in the lungs. Because the partial pressure of oxygen is higher in the alveoli than in the blood, oxygen diffuses into the blood and is transported to systemic cells. • At the tissues the par...

Membrane transport proteins - pores, gated channels and pumps

By: HWC, Views: 6765

• a Three different types of membrane ion transport proteins are required to produce and carry electrical signals: • Pores • Gated channels • Na+/ K+ pump • Pores are always open and allow the diffusion of Na+ and K+ ions across the membrane, down their concentration gradients...