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Enzyme-Catalyzed Reactions

By: HWC, Views: 7180

S P Substrate in great excess ([S] -- [E]) (More correctly [S] -- KM, but more on this later) Zero order rate equation: v = k where k is the zero-order rate constant (with respect to substrate). (More correctly [S] -- KM, but more on this later) Substrate forms complex with enzyme. ...

Plant Defense Mechanisms from Pathogens

By: HWC, Views: 7183

Plants and pathogens have coevolved such that pathogens can recognize plants by the sugars, or other molecules, they produce. Plants, in turn, can recognize pathogens by the molecules they produce. The ability to recognize pathogens allows plants to activate defense systems that can prevent wides...

Red Blood Cells - Erythropoietin (EPO)

By: HWC, Views: 7711

• 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...

Graded potentials - electrical characteristics and types

By: HWC, Views: 7983

• A graded potential occurs when a gated channel is opened or closed, altering ion flow through the membrane. • Changes in ion and charge distributions cause voltage changes to the resting membrane potential. • The strength of the stimulus determines the number of gated channels affect...

Egg and Sperm Formations in Animals Animation

By: HWC, Views: 1969

Inside the ovaries of a female animal are diploid germ cells called oogonia. An oogonium grows to become a primary oocyte. This large cell is still diploid. Meiosis I followed by unequal cytoplasmic division produces one large secondary oocyte and a smaller polar body. Both are haploid. ...

Components of the Nervous System

By: Administrator, Views: 433

The nervous system is the part of an animal that coordinates its actions by transmitting signals to and from different parts of its body. The nervous system detects environmental changes that impact the body, then works in tandem with the endocrine system to respond to such events. Nervous tissue...

Stages of Mitosis - Prophase, Prometaphase, Metaphase, Anaphase & Telophase

By: HWC, Views: 7426

In mitosis, the nucleus divides to produce two nuclei that are genetically identical to each other and to the parent nucleus. To prepare for division, the DNA replicates in the preceding interphase. Although the chromosomes are not yet compacted and visible as discrete bodies, we illustrate them ...

Miller's reaction chamber experiment Animation

By: HWC, Views: 1302

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. ...

Dendrite Animation

By: Administrator, Views: 11206

Dendrites (from Greek δένδρον déndron, "tree"), also dendrons, are branched protoplasmic extensions of a nerve cell that propagate the electrochemical stimulation received from other neural cells to the cell body, or soma, of the neuron from which the dendrites project. Electrical stimula...