2 Energy 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
3 Autotrophs 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
4 Autotrophs and Heterotrophs Heterotrophs: organisms that obtain energy from the food they consumeOrganisms dependent on consuming other organisms for foodExamples: animals (us ) and fungi
5 Chemical 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
6 Chemical Energy and ATP ATP (Adenosine Triphosphate): chemical compound living things use to store and release energy
7 Chemical Energy and ATP ATP structure:Adenine3 phosphategroupsRibose
8 Chemical 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!
9 Chemical Energy and ATP The resulting molecule is called ADPAdenosine DiphosphateIt can have phosphate groups re-attached to be used againEnergy!
10 Chemical 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
11 Using Biochemical Energy Most energy in a cell is used for active transportAlso used for protein synthesis, contracting muscle cells, etc.All life processes
12 Using Biochemical Energy Cells keep a small supply of ATP on handCells regenerate ATP from ADP using energy in food molecules like glucoseDone by mitochondria
13 Using 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
14 Using 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