Energy in Cells

Metabolism The total of all chemical activities of an organisms that enables it to stay alive, grow and reproduce. Chemical energy – stored in food in the cell - can be changed into other forms of energy Heat, kinetic energy

enzymes Causes a chemical reaction Does not change Can be reused Each chemical reaction has a specific enzyme Causes molecules to come apart or come together

How enzymes work

2 groups of organisms Producers – make their own food Consumers – eat producers and/or other lower consumers Energy is changed chemically from one to the other.

Photosynthesis Changing sunlight into chemical energy Chloroplasts – where photosynthesis takes place

Photosynthesis 6CO2 + 6H2O + sunlight + chlorophyll  (C6H12O6) +6O2

Chlorophyll absorbs energy from sun Sun’s energy splits H2O and CO2 into C6H12O6 + O2 O2 given off through leaves Glucose – chemical/ stored energy

Glucose 1. use for plant energy 2. stored as starches (carbohydrates) to be used later

Respiration Breaking down of food to release energy Mitochondria – where respiration takes place Sugar + O2  CO2 + H2O + energy (lost as heat) kinetic /moving electrical energy

Fermentation Changing glucose into energy with little oxygen Less energy produced Takes place in the cytoplasm Makes lactic acid that gets into the muscle fibers and causes cramps.