Post on 13-Jul-2015
transcript
CO2 + H2O + heatfuel
(carbohydrates)
O2
“Burn fuels” to make energycombustion
making heat energy by burning fuels in one step
ATP
ATP + CO2 + H2O (+ heat)
aerobic respiration
making ATP energy (& some heat) by burning fuels
in many small steps
food
(carbohydrates)
O2
Energy needs of life• Animals are energy consumers
• What do we need energy for?
• synthesis (building for growth)
• reproduction
• active transport
• movement
• temperature control (making heat)
Where do we get energy?• Energy is stored in organic molecules
• carbohydrates, fats, proteins
• Animals eat these organic molecules food
• digest food to get
• fuels for energy (ATP)
• raw materials for building more molecules
• carbohydrates, fats, proteins, nucleic acids
ATP
Harvesting energy stored in food• Cellular respiration
• breaking down food to produce ATP
• in mitochondria
• using oxygen = “aerobic” respiration
• usually digesting glucose
• but could be other sugars, fats, or
proteins O2
food
ATP
C6H12O6 O2 CO2
ATP
H2O
Glucose Oxygen Carbon
DioxideWater
ATP
What do we need to make energy?
• The “Furnace” for making energy
• mitochondria
• Fuel
• food: carbohydrates, fats, proteins
• Helpers
• oxygen
• enzymes
• Product
• ATP
• Waste products
• carbon dioxide
• water
O2
food
ATP
Make ATP!Make ATP!
All I do all day…And no oneeven notices!
enzymes
CO2 H2O
Cannot store ATP too unstable
only used in cell that produces it
only short term energy storage carbohydrates & fats are long term energy storage
Using ATP to do work?
A working muscle recycles over
10 million ATPs per second
Whoa!Pass me the
glucose & oxygen!
ATP
ADP
workAdenosine DiPhosphate
Adenosine TriPhosphate
How organisms turn fuel into ATP
Fuel(carbohydrates, lipids, proteins)
Anaerobic
Cellular Respiration
Oxygen present?
no yes
Alcoholic
FermentationLactic Acid
Fermentation
Makes only a little
Aerobic
Cellular Respiration
ATP
ATP
ATP ATP ATP
ATP
ATP
ATP
ATPATPATP
ATP
Makes a LOT of
Aerobic Cellular Respiration
3 Major Steps:
1. Glycolysis
2. Kreb’s Cycle / Citric Acid Cycle
3. Electron Transport Chain
1. Glycolysis
• Glyco = glucose lysis = splitting
• Where: in the cytoplasm
• Uses : glucose but NO oxygen
• Makes:
• Pyruvate (passed to Kreb’s Cycle)
• A little ATP
• NADH (electron bus… headed to the
Electron Transport Chain)
2. Krebs Cycle
• Where?
• in the mitochondrial matrix
• Uses:- pyruvate (from glycolysis)
• Makes:
• NADH (electron bus)
• FADH2 (electron bus)
• A little ATP (energy)
• Carbon Dioxide (waste product)
3. Electron Transport• Where?
• Inner mitochondrial membrane
• Uses:
• NADH & FADH2
• Remember these are like “electron buses” that drop off electrons to the ETC
• Oxygen
• Pulls electrons down the ETC and accepts them at the end of the ETC
• This is why we die if we don’t get oxygen!
• Makes:
• Water (waste product)
• A BUNCH of (whoohooo… big energy!)ATP
How does the ETC make so much
energy ?
Answer = chemiosmosis
Sound familiar?
• We learned it in photosynthesis too!
ATP
1. NADH & FADH2 drop off electrons
1. Oxygen pulls electrons down the ETC
2. Chemiosmosis = Hydrogen ions diffuse
from an area of high concentration
(outside the membrane) to an area of
low concentration (inner-membrane
space) through ATP synthase.
• Hydrogen ions then help to bond a
third phosphate group to ADP creating
lots of ATP
Electron Transport
Anaerobic Respiration
We know that aerobic cellular
respiration requires oxygen. But
what happens if there is no oxygen
available?
Answer = Anaerobic Cellular Respiration
O2
Anaerobic respiration
• The anaerobic pathway that follows glycolysis
• If there is no oxygen present and an organism needs energy, the cell may use anaerobic respiration to continue producing ATP
O2
Anaerobic Respiration
• also known as fermentation
• alcohol fermentation
• lactic acid fermentation
• no oxygen or
no mitochondria (bacteria)
• makes very little ATP
• large animals cannot survive
using only fermentation
O2
yeast
bacteria
Anaerobic Respiration• Fermentation
• alcohol fermentation
• yeast
• glucose ATP + CO2+ alcohol
• make beer, wine, bread
• lactic acid fermentation
• bacteria, animals
• glucose ATP + lactic acid
• bacteria make yogurt
• animals feel muscle fatigue
O2
Tastes good…but not enoughenergy for me!
What is the overall purpose of cellular
respiration?
A. to make ATP
B. to produce H2O
C. to store glucose
D. to deliver oxygen
Which represents the general sequence of
cellular respiration?
A. TCA cycle chemiosmosis glycolysis
B. glycolysis Krebs cycle electron transport
C. electron absorption catalysis
phosphorylation
fermentation
D. aerobic pathway anaerobic pathway
Which stage of cellular respiration is the
anaerobic process?
A. glycolysis
B. Krebs cycle
C. electron transport