CHAPTER 8 Cellular Energy 8-1 How Organisms Obtain Energy.
-
Upload
lionel-norris -
Category
Documents
-
view
240 -
download
0
Transcript of CHAPTER 8 Cellular Energy 8-1 How Organisms Obtain Energy.
CHAPTER 8 Cellular Energy
8-1 How Organisms Obtain Energy
JOURNALWhat are some of the different forms of energy?
What do organisms need energy for?
Launch Lab: How is Energy Transformed? Page 216 The flow of energy in living systems is
driven by a variety of chemical reactions and chemical processes. Energy is transformed from the Sun’s radiant energy to chemical energy to other forms of energy along the way. In this lab, you will observe two processes in which energy is transformed.
Transformation of Energy
Energy is the ability to do work.
Cellular Energy
Thermodynamics is the study of the flow and transformation of energy in the universe.
Laws of Thermodynamics
First law “Law of Conservation of Energy”
energy can be converted from one form to another, but it cannot be created nor destroyed.Example: Stored energy in food is converted to chemical energy when you eat, and then mechanical energy when you kick a ball.
Laws of Thermodynamics
Second law “Entropy increases” energy cannot be converted without the loss of usable energy. Energy that is “lost” is usually
converted to thermal energy Example – energy lost in food chains
Entropy is the measure of disorder, or unusuable energy, in a system
Autotrophs and Heterotrophs Autotrophs are organisms that make their own
food. Heterotrophs are organisms that need to
ingest food to obtain energy.
MetabolismAll of the chemical reactions in a cell
Catabolic Pathways – Release energy by breaking down large molecules into smaller molecules
Anabolic Pathways - Use the energy released by catabolic pathways to build larger molecules from smaller molecules
Result in the continual flow of energy in an organism
ANABOLIC PATHWAYPhotosynthesis
light energy from the Sun is converted to chemical energy for use by the cell
CATABOLIC PATHWAYCellular respiration
organic molecules are broken down to release energy for use by the cell
Metabolic PathwaySeries of chemical reactions in which the product of one reaction is the substrate for the next reaction
Photosynthesis(autotrophs)
Cellular Respiration(heterotrophs &
autotrophs)
Adenosine TriphosphateThe cell’s key to being able to store and
release energy
ATP: The Unit of Cellular Energy
ATP: The Unit of Cellular Energy
ATP releases energy when the bond between the second and third phosphate groups is broken, forming a molecule called adenosine diphosphate (ADP) and a free phosphate group.
ATP
ATP can easily release and store energy by breaking and re-forming the bonds between its phosphate groups. This characteristic of ATP makes it exceptionally useful as a basic energy source for all cells.
Quick CheckWhat is energy?The ability to do workCan energy be created? NoCan energy be destroyed?No
List some forms of energy.Thermal/heat, mechanical, chemical, lightAnalyze why living things need energy.To grow, to move, to reproduce, to break down food, etc…How do humans obtain energy?By eating and digesting food
Journal
Explain how ADP and ATP are like a battery in the cell. Which one is partially charged and which one is fully charged?
JOURNAL
Using vocabulary from 8-1, discuss the metabolic pathway that includes photosynthesis and cellular respiration.
JOURNAL
Explain how the ultimate source of energy for heterotrophs is the sun even though they cannot make their own food.
energy
thermodynamics
metabolism
Photosynthesis
cellular respiration
adenosine triphosphate (ATP)
Cellular Energy
Vocabulary
Section 1