Search Results

ATPase function - membrane transport, contractile proteins and synthesis

By: HWC, Views: 8104

• Energy from ATP is used to move ions across the cell membrane during active transport. • This membrane protein transports sodium out of the cell and potassium into the cell. As such, it is called a sodium-potassium pump. • Because this pump also acts as an enzyme to hydrolyze ATP it i...

Simple Diffusion - gases and nonpolar compounds transport

By: HWC, Views: 8050

Gases and some molecules can diffuse through the phospholipid bilayer because they are small or non-polar. Oxygen gas. Carbon dioxide gas. Lipid based hormones. Plasma membranes are selectively permeable: The lipid bilayer is always permeable to small, nonpolar, uncharged molecules ...

What is Reverse Osmosis?

By: HWC, Views: 5451

Osmosis is when a solvent, such as water, moves from a low-solute concentration solution to a higher-solute concentration solution through a semipermeable. Osmosis is an example of diffusion (a special case of diffusion) in which the molecules are water, and the concentration gradient occurs a...

What is Reverse Osmosis?

By: HWC, Views: 4985

Osmosis is when a solvent, such as water, moves from a low-solute concentration solution to a higher-solute concentration solution through a semipermeable. Osmosis is an example of diffusion (a special case of diffusion) in which the molecules are water, and the concentration gradient occurs a...

Calvin cycle (The light-independent reactions )

By: HWC, Views: 7489

The light-independent reactions of photosynthesis occur in the stroma of the chloroplast. Carbon dioxide enters the leaf through tiny pores or stomata and diffuses into the chloroplast. The first stage of the Calvin cycle is the attachment of a carbon dioxide molecule to a 5-carbon ribulose bi...

Gas exchange - driving force

By: HWC, Views: 7804

• The respiratory system is responsible for the movement of gases involved in cellular metabolism. • Oxygen is used up and carbon dioxide is generated during the aerobic breakdown of glucose and other fuel molecules in order to produce ATP. • Three important continuous physiological pro...

How Hemoglobin Picks Up and Delivers Oxygen

By: HWC, Views: 7039

All of the cells in our bodies require oxygen (02) for survival and must release carbon dioxide (CO2) as a waste product. The respiratory and circulatory systems work together as delivery systems for these gases. The lungs exchange these gases between the environment and the bloodstream. The bloo...

Protein digestion - stomach & small intestine

By: HWC, Views: 7206

• 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...

Energy sources - types

By: HWC, Views: 7924

• The amount of ATP stored in a skeletal muscle cell can only provide muscular activity for two to three seconds. • Muscle cells must be able to generate additional molecules of ATP to continue contracting. • Muscle cells can generate ATP from several processes: • Phosphogen syste...