3.3. nutrition and energy systems
DESCRIPTION
3.3. NUTRITION AND ENERGY SYSTEMS. IB SEHS. Starter. What distinguishes animal cells versus plant cells ? Where does respiration occur ?. Learning Objectives. Everyone will be able to Identify the different parts of the mitochondrion. 2. Define and understand respiration - PowerPoint PPT PresentationTRANSCRIPT
3.3. NUTRITION AND ENERGY SYSTEMS
IB SEHS
Starter
• What distinguishes animal cells versus plant cells?
• Where does respiration occur?
Learning Objectives
Everyone will be able to 1. Identify the different parts of the
mitochondrion.
2. Define and understand respiration
3. Explain the loss and gain of phosphate in an adenosine molecule
The Animal Cell
Mitochondrion Ultrastructure
• Energy provision • Only site where
oxygen is used• Location: All cells,
but red cells• Ultrastructure
shown right
The Energy currency, ATP
• ATP is the energy currency • Adenosine TriPhosphate is a molecule created
from biochemical energy in organic molecules by catabolic reactions.
Cell Respiration
• Cell respiration is the controlled release of energy in the form of ATP from organic compounds in cells
Energy metabolism: ATP
• ATP connects anabolic and catabolic reactions. • Ingested food stored as fats or glycogen
Catabolism ATP Energy
ATP role in muscle contraction
• Actin and myosin use ATP to drive contraction
• Muscle fibers have sufficient ATP for only 2 seconds of contraction. The rest comes from catabolic reactions that generate ATP
• ATP + H2O ADP + P + Energy Contraction
Anaerobic Energy Systems Creatine Phosphate System
• Creatine Phosphate SystemCP is another high energy molecule BUT cannot be used directly. It´s a check we need to first cash into ATP.
• During exercise, after spending our 2 sec worth of ATP, CP helps re-synthesizing ATP, giving energy for up to first 20 sec to muscles
Creatine Phosphate System goes both ways
• The ATP-CP system can go both ways. – During exercise, first 20 sec, ATP is re-synthesized– At rest, ATP can be used to refill our store of PCr in
the muscle
REST <--- --->EXERCISE
Anaerobic Energy Systems Lactic Acid System
• Anaerobic Glycolysis LOCATION: CYTOPLASM of all cells
Glucose ATP + pyruvate • Limited supply of oxygen or
mithocondria leads to Pyruvate Lactate + 2 ATP
• Lactic Acid System is quick and ideal of hard exercise
Anaerobic Energy Systems Lactic Acid System
• Is the Lactic Acid System an ideal system for an elongated period of hard exercise?
• Interpret and comment on the following graph
Aerobic Energy Systems
• Location: MITOCHONDRIA– Electron transport chain
in the inner membrane – Krebs Cycle in the
matrix– β-oxydation in the
matrix
Aerobic Energy Systems
• Glucose Oxydation – Pyruvate acetil CoA Krebs Cycle in the matrix– H+ ions released ELECTRON TRASPORT CHAIN ENERGY AS ATP
Aerobic Energy Systems
• Fat Oxydation– Free fatty acids enter the matrix β-oxydation
Acetil CoA Krebs Cycle H+ Electron transport chain Energy as ATP
– Fat CANNOT BE USED ANAEROBICALLY,unlike glycogen
STARTER
• Discuss in pairs what is the determiant factor for cells to use one energy system or another. Explain in detail.
What Energy System is this one? What is the limitant factor?
THE BIG QUESTION
• How does the elenctron tranport chain help the cell synthesizing ATP?
• https://www.youtube.com/watch?v=Ak17BWJ3bLg
INDIVIDUAL ACTIVITY
• YOU HAVE RECEIVED A MUSCLE CELL (LONG WHITE PAPER)
• DRAW A DIAGRAM, INCLUDING CELL MEMBRANE, CYTOSOL AND MITHOCONDRION WITH DETAIL, IN WHICH THE THREE METABOLIC PATHS ARE SHOWN: ANAEROBIC LACTIC ACID, GLUCOSE AND FATTY ACID OXYDATION. INCLUDE MAIN REACTIONS ONLY
• BE READY TO EXPLAIN YOUR CELL.
Oxygen Deficit and Excess Post-Exercise Oxygen Consumption (EPOC)
• Start of exercise Oxygen need > oxygen supply: O2 DEFICIT ATP, PCr and anaerobic glycolysis activate quicker!
• After exercise Oxygen supply greater than needed: EPOC or O2 DEBT offset consequences of anaerobic metabolism, repair of tissue, myoglobin oxydation, etc.
Oxygen Deficit and Excess Post-Exercise Oxygen Consumption (EPOC)
• Analyze and comment on the following graph:
Contribution of the Energy Systems during exercise
• High intensity exercise high rate of ATP needed Fast metabolism PCr (20 sec) and Lactic Acid System
• Longer & Slower exercise Aerobic metabolism: Glucose and Fat oxydation (slowest one)
• Glucose (anaerobic and aerobic) metabolism is key across all intensities of exercise.
Contribution of the Energy Systems during exercise
Different types of exercise and energy systems contribution