Biochemistry Notes-study guide

Biochemistry Notes

Energy transfer through cells

from www.sirinet.net/~jgjohnso/ photorespiration.jpg

Photosynthesis

from http://www.ftexploring.com/photosyn/photosynth.html

CO2+H2O+water -> sugar + O2

Two parts

Light reaction: hydrogen is removed from water to form oxygen

Dark reaction: carbon dioxide is converted to sugar.

Opposite reaction to respiration

Takes place in the chloroplasts (using chlorophyll)

Respiration

sugar + oxygen -> energy + carbon dioxide

Completely the opposite of photosynthesis

takes place in the mitochondria of cells

Biochemistry Notes

Respiration

takes place in the mitochondria of cells

2 parts

aerobic respiration -- takes place in the presence of oxygen

anaerobic respiration -- takes place without oxygen

also called fermentation

produces alcohol (plants) or lactic acid (muscles)

energy released from glucose converted to a more available form of energy

ATP <-> ADP + P + energy

C6H12O6 + 6O2 -> 6H2O + 6CO2 + 36 ATP

Organic molecules

Elements

top 3: carbon, hydrogen, oxygen

next 2: nitrogen, sulfur, phosphorous

Bonds

Structure

Organic Compounds

Carbohydrates

Made up of sugars

Elements: carbon, hydrogen, oxygen

Proteins

Made up of amino acids

Elements: carbon, hydrogen, oxygen, nitrogen, and sulfur

Lipids/Fats

Made up of fatty acids and glycerol

Elements: carbon, hydrogen, oxygen (just like carbs)

Enzymes

Enzymes are proteins

Enzymes speed up the process of just about every chemical reaction in a cell.

They are called catalysts

Enzymes work according to the lock and key theory

Enzymes attache to substrate at active site

This "connection" serves to speed up a chemical reaction

When reaction is completed, enzyme and substrate separate.

from RegentsPrep.org

Structure determines function

Factors influencing enzyme function

pH

7 is optimal

too high or too low is no good.

Biochemistry Notes

Enzymes

Enzymes work according to the lock and key theory

Factors influencing enzyme function

pH

too high or too low is no good.

temp

too high - enzyme is denatured (destroyed)

too low - not enough energy for reaction

concentrations of enzyme and substrate

too much of one and/or too little of the other is no good.

Basic Concepts

Chemical elements tend toward stability

adding or losing electrons

organic compounds are the result of this trend toward stability

Structure is the key to biochemistry

example: lock and key theory for enzymes, neurotransmitters

Energy moves from where there's more to where there is less

2nd principle of thermodynamics: entropy increases toward randomness

Organic systems seek to maintain homeostasis

maintenance of stable internal environment despite changes to external environment.

Dynamic equilibrium

The process of various cellular and organ systems working together to maintain the homeostasis of a living, complex organism

Systems rely on feedback mechanisms

example: thermostat and furnace

feedback can be neural (nerve messages) or chemical (hormones, blood levels)

Surface area

Many body systems make use of increased surface area

Allows systems to do a lot of processing in a relatively small space

Example: digestive system