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Photosynthesis and Van Helmont Experiment

By: HWC, Views: 5943

All energy on Earth comes from a star, the Sun. Light must travel 160 million kilometers to reach Earth where plants capture this light energy and convert it to chemical energy in the form of sugars. This biochemical process is called PHOTOSYNTHESIS. The summary equation for photosynthesis is ...

Protein Structure - Primary, Secondary, Tertiary and Quaternary

By: HWC, Views: 6656

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...

Kinetic parameters & Kinetic experiment

By: HWC, Views: 6509

Kinetics is a measure of the speed or rate of a chemical reaction. A study of kinetics allows us to determine which variables to control (temperature, reactants, catalysts) and how to vary them in order to maximize the amount of products formed and minimize the time involved. Vmax = maximum ve...

A Human Karyotype Preparation Animation

By: HWC, Views: 3858

Blood is collected from the person being analyzed. The blood is added to a growth medium that also contains a chemical that stimulates mitosis. The cells are allowed to grow in this medium for two or three days at body temperature. Colchicine is added to arrest cell division at metaphase. T...

Resting membrane potential - electrical polarity and maintenance requirements

By: HWC, Views: 6464

• A resting membrane potential exists when there is a buildup of: 1. positive ions outside the membrane. 2. negative ions inside the membrane. • Membranes with opposing charges are said to be polarized. • The difference in charge applies only to the small distance across the membran...

Calvin cycle (The light-independent reactions )

By: HWC, Views: 6429

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...

Electromagnetic Spectrum, Chlorophyll and Pigment & Light

By: HWC, Views: 6379

The sun gives off radiation that is called the electromagnetic spectrum. This is energy that travels as wavelengths and includes radio waves, X-rays and ultraviolet light. A portion of this radiation is known as visible light, and is the type of radiation that plants use to manufacture sugars. ...

Red Blood Cells - Erythropoietin (EPO)

By: HWC, Views: 6684

• The endocrine system maintains many body conditions within normal limits with feedback loops. Each endocrine feedback loop maintains homeostasis using the following components: • Stimulus - a change in a body condition. • Production cell - an endocrine cell that produces a hormone aft...

Miller's reaction chamber experiment Animation

By: HWC, Views: 288

A simple diagram of Stanley Miller and Harold Urey's experimental apparatus. The lower portion of the apparatus was filled with water. The upper portion was filled with a mixture of gases that simulated the earth's early atmosphere. Examples are methane, ammonia, hydrogen and carbon dioxide. ...