2Energy Energy is the ability to do work Work can be playing a sport, thinking, or building a protein in a cellAll living things obtain and use energy
3Autotrophs and Heterotrophs Autotrophs: organisms that use light energy from the sun to make foodOrganisms that do photosynthesis or something similar to obtain energyExamples: plants and algae
4Autotrophs and Heterotrophs Heterotrophs: organisms that obtain energy from the food they consumeOrganisms dependent on consuming other organisms for foodExamples: animals (us ) and fungi
5Chemical Energy and ATP Energy comes in many formsExamples: light, heat, electricity, kinetic energy, potential energyMost energy used in living systems comes from breaking chemical bonds
6Chemical Energy and ATP ATP (Adenosine Triphosphate): chemical compound living things use to store and release energy
7Chemical Energy and ATP ATP structure:Adenine3 phosphategroupsRibose
8Chemical Energy and ATP Energy is stored in the bonds between the phosphate groupsEnergy is released when the bonds between the second and third phosphate is brokenEnergy!
9Chemical Energy and ATP The resulting molecule is called ADPAdenosine DiphosphateIt can have phosphate groups re-attached to be used againEnergy!
10Chemical Energy and ATP Cells keep a lot of ADP on handWhen energy becomes available cells store it by adding a third phosphate to an ADPMaking ATPWhen a cell needs to do work the third phosphate is broken off, releasing energy
11Using Biochemical Energy Most energy in a cell is used for active transportAlso used for protein synthesis, contracting muscle cells, etc.All life processes
12Using Biochemical Energy Cells keep a small supply of ATP on handCells regenerate ATP from ADP using energy in food molecules like glucoseDone by mitochondria
13Using Biochemical Energy A single glucose molecule contains 90 times more energy than an ATP moleculeJobs done in a cell require tiny amounts of energyWe couldn’t consume enough food to maintain life if a glucose molecule were consumed for each cellular job
14Using Biochemical Energy Making ATPs from glucose is like “making change”Similar to having 100 $1 bills instead of a $100 bill if all you need is a candy bar