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Flashcards in Chapter 1.7 Deck (14)
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Describe Metabolism

All Chemical reactions of the body


Describe Catabolism

Energy Releasing (exergonic) decomposition reactions:

-breaks covalent bonds
-produces smaller molecules
-releases useful energy


Describe Anabolism

Energy Storing (endergonic) synthesis reactions:

-requires energy input
-production of protein or fat
-driven by energy that catabolism releases

inseparably linked to catabolism


What is Oxidation?

Any chemical reaction in which a molecule gives up electrons and releases energy.

Molecule is Oxidized in this process

Electron acceptor molecule is the oxidizing agent


What is Reduction?

Any chemical reaction in which a molecule gains electrons and energy

Molecule is reduced when it accepts electron

Molecule that donates electrons is the reducing agent


What happens in an Oxidation-Reduction reaction?
(AKA Redox reaction)

Oxidation of one molecule is always accompanied by the reduction of another

Electrons are often transferred as hydrogen atoms


Define Homeostasis

The body's ability to detect change, activate mechanisms that oppose it and thereby maintain relatively stable internal conditions.

**loss of homeostatic control causes illness or death

Coined by Walter Cannon


What is a Negative Feedback Loop?

Body sense a change and activates mechanisms to reverse it - dynamic equilibrium

Think of thermostat example, heat is turned on when too cold and turned off when too hot.


How does thermoregulation work?

Brain senses change in blood temperature. If too warm, vessels dilate (vasodilatation) in the skin and sweating begins, thus losing heat.

if too cold, vessels constrict (vasoconstriction) and shivering begins, thus gaining heat


Describe Negative feedback control of Blood Pressure

Sitting up in bed causes a drop in blood pressure in the head and upper thorax.

Baroreceptors in the arteries near the heart alert the cardiac center in the brainstem

Cardiac center send nerve signals that increase the heart rate and return the blood pressure to normal


What does a receptor do in relation to feedback control?

Sense change in the body


What does the Integrating (control) center do?

control center that processes the sensory information and "makes a decision" and directs the response


What does an Effector do in feedback control?

Carries out the final corrective action to restore homeostasis


What makes up a Positive Feedback Loop?

Self-amplifying cycle: greater change in the same direction, feedback loop is repeated and change produces more change

Normal way of producing rapid changes: occurs with childbirth, blood clotting, protein digestion, fever and generation of nerve signals