Chater 8 and 9 Energy in Living Organisms

CELL METABOLISM• Metabolism

o The chemical processes occurring within a living cell

o Necessary for maintaining lifeo Useso _____________________materials the cell needs

enzymes

Breaks down or builds

Enzymeso Are ____________o Required for every chemical reaction in an organismoWithout, would not be able to maintain ___________

Don’t make the reaction happen that couldn’t happen on its own

oMake the reaction occur much _____

proteins

homeostasis

faster

• Function of Enzymeso Serve as _________oWork by lowering the _______________

energy required to get the reaction started

catalysts

activation energy

• Characteristics of EnzymesoWork best in a narrow ______________________o They are not changed or used up in the reaction;

can be _______________ againo They are_______________; because of their_____• _________- surface to which the enzyme binds • __________- where substrate binds and

undergoes a chemical reaction

pH & temperature range

used over & over

substrate-specific shape

Substrate

Active site

BREAKING DOWN MOLECULES

BUILDING MOLECULES

CELL ENERGY• Energy is the ____________________• ____________: Organisms that obtain energy from

consuming food• ____________: Organisms that use sunlight or

chemicals to convert inorganic compounds into food for energy.

o Example: Plants – use the process of_____________, to make their own food. This process occurs in the ____________

o The equation for photosynthesis:

ability to do workHeterotrophs

Autotrophs

photosynthesis

chloroplasts

CO2 + H2O + energy → C6 H12 O6 + O2

ATP

Chemical Energy• Stored in ______________• Potential energy

oWhen bonds are broken; converted to _____________in the form of ____

• Food molecules cannot be used directlyo The amount of energy

released would be ________and __________

chemical bonds

useable energy

ATP

wasteful destructive

ATP- Adenosine Triphosphateo____________composed of:• Nitrogen base - ________• 5-carbon sugar- ________• __phosphate groups ATP

Nucleotide

adenineribose

3

• Energy is stored in ________________________bonds. • ATP works like a _____________________. • Cells are able to use and recycle ATP by ____________

________________a phosphate group

o Energy is _________ when the phosphate bond is broken

o ATP is converted to _____________ ____________

o ADP is like an “____________” battery

o Energy is _______ when phosphate bond is added to ADP making ATP• ATP is “__________” like a fully

charged rechargeable battery

phosphate – phosphaterechargeable battery

breakingoff or adding

released

ADP- adenosinediphosphate

unchargedstored

recharged

Like a Rechargeable Battery

Phosphate bonds

ATP – ADP CYCLE

• Aerobic energy production

o Breakdown of glucose in presence of oxygeno Produces ATPo Occurs in mitochondria of eukaryotic cells o Equation for cellular respiration• C6 H12 O6 + O2 → CO2 + H2O + energy (ATP)

Cellular Respiration

2 2 34

2

CELLULAR RESPIRATION

o Glycolysis• Occurs in cytoplasm• Uses 1 glucose molecule and O2

• Produces 2 Pyruvic acids, 2 ATP’s and high energy e-o Krebs Cycle• Occurs in outer membrane of mitochondria• Produces CO2 as waste, 2 ATP’s and high energy e-

o Electron Transport Chain• Occurs in the inner membrane of mitochondria• Uses O2 and high energy electrons from first 2 steps

• Produces H2O and 32 ATP’s

3 STEPS TO CELLULAR RESPIRATION

GLYCOLYSIS

KREBS CYCLE

ELECTRON TRANSPORT CHAIN

1 GLUCOSE STAGE WHERE # ATP

GLYCOYSIS CYTOPLASM 2KREBS CYCLE

OUTERMITOCHONDRIA 2

ELECTRONTRANSPORT

CHAIN

INNERMITOCHONDRIA 32

TOTAL ATP GAIN IN CELLULAR RESPIRATION 36 ATP per MOLECULE

OF GLUCOSE

Fermentation • Anaerobic Energy Production o Occurs if oxygen is not available o Glycolysis still takes place o 2 ATP’s are made for 1 glucose

• 2 types:o Lactic acid fermentationo Alcoholic fermentation

Lactic Acid Fermentation: Produces Lactic acid• Human Muscle Cells

o Occurs when muscles run out of oxygeno Muscle switches to fermentationo Lactic acid builds up; causes pain, soreness & fatigueo Will switch back to Cellular Respiration when oxygen

is re-suppliedo Lactic acid is sent to liver to be broken down

• Bacteriao some bacteriao during anaerobic conditionso Utilized by dairy industry to produce yogurt & cheese

Alcoholic Fermentation: Produces alcohol and CO2

• Occurs in Yeast during anaerobic conditions• Important in brewing & baking industries

TOTAL ATP GAIN IN FERMENTATION

2 ATP per MOLECULE OF GLUCOSE

Process in which energy of sunlight is used to convert water and carbon dioxide into high-energy carbohydrates (sugar and starches) and oxygen, a waste product

Factors affecting photosynthesis• Temperature

• photosynthesis depends on enzymes that function best between 0o and 35o C

• Availability of water• Shortage of water can slow or even stop photosynthesis

• Amount of Light• Increasing light intensity increases the rate of photosynthesis

PHOTOSYNTHESIS

Light and Pigments

• In addition to water and carbon dioxide, photosynthesis requires light and chlorophyll, a molecule found in chloroplasts.

• Pigment: light absorbing moleculeo Principal pigment is chlorophyllo 2 main types

• chlorophyll a • chlorophyll b

• Energy absorbed by chlorophyll is transferred directly to electrons in the chlorophyll o Makes photosynthesis possible

• These high-energy electrons are used to help build carbohydrates.

COMPARING PHOTOSYNTHESIS AND CELLULAR RESPIRATION

Photosynthesis • Occurs in the chloroplast• Uses sunlight to convert H2O and CO2

into high energy sugars and O2

• uses water and light• splits water and releases O2

• produces O2 and glucose

Cellular Respiration• Occurs mostly in mitochondria• Uses O2 and glucose to produce H2O,

CO2 and ATP• uses oxygen and glucose• produces carbon dioxide, water and

energy (36 ATP)