6. GLYCOLYSIS means “sugar splitting”

8. Kreb Cycle

11. Proteins embedded along inner membrane of mitochondria

18. Pyruvate reduced by NADH to:
Lactate
Animals & some bacteria
Cheese & yogurt; sauerkraut
Ethanol & carbon dioxide
Yeasts
Bread and alcoholic beverages
Allows glycolysis to proceed faster than O2 can be obtained
Anaerobic exercise
Lactic acid accumulates
Causes cramping and oxygen debt
When O2 restored, lactate broken down to acetyl-CoA and metabolized

19. Aerobic Vs Anaerobic Efficiency
CALORIES??????

20. Exercise – test of homeostasis
Muscle contracts – increases demand for _______
This increases the demand for A) B)
Oxygen debt –
As training continues –

22. Test your oxygen debt
Breathing rate = number of inhalations per minute
Initial rate
After exercise
5 minutes after exercise

23. The Demand for ATP WHY EXACTLY DO YOUR MUSCLES NEED ATP?
41.3 in textbook

25. Microscopic Anatomy and Physiology
Sarcolemma
Plasma membrane
Sarcoplasmic Reticulum
Modified endoplasmic reticulum
Myofibrils
Contractile structures in sarcoplasm
Sarcomeres
Units of contraction
Consist primarily of proteins
Myosin
Actin

26. Skeletal Muscle Fiber Structure and Function

27. Muscle Contraction
Sliding filament model

29. Neuromuscular Junction

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CopyrightThe McGraw-Hill Companies, Inc. Permission required for reproduction or display.

31. Neuromuscular Junction
CopyrightThe McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Neuromuscular Junction
1. The site where the motor neuron and muscle fiber meet is the neuromuscular junction.
a. The muscle fiber membrane forms a motor end plate in which the sarcolemma is tightly folded and where nuclei and mitochondria are abundant.
b. The cytoplasm of the motor neuron contains numerous mitochondria and synaptic vesicles storing neurotransmitters.

32. CopyrightThe McGraw-Hill Companies, Inc
CopyrightThe McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Motor Units
1. A motor neuron and the muscle fibers it controls make up a motor unit; when stimulated to do so, the muscle fibers of the motor unit contract all at once.

33. Muscle Contraction Sliding filament model
Depolarization of muscle causes sarcoplasmic reticulum to release Ca2+

34. Muscle Contraction Sliding filament model
Ca2+ exposes binding sites on actin
Myosin heads bind to actin
Cross bridges form

36. Muscle Contraction Sliding filament model Myosin heads lose ADP + P
Myosin heads change shape
Actin pulled toward center of sarcomere
Muscle contracts

37. Muscle Contraction Sliding filament model ATP binds to myosin heads
Cross bridges break
Muscle relaxes

38. Muscle Contraction
Sliding filament model

40. Sliding Filament Model
Actin filaments at both ends of sarcomere
One end of each filament attached to a Z-plate at one end of the sarcomere
Other end suspended in sarcoplasm
Myosin filaments suspended in between Z-plates
Myosin filaments contain cross-bridges which pull the actin filaments inward
Causes Z-plates to move toward each other
Shortens sarcomere
Sarcomeres stacked together in series and cause myofiber to shorten
Working muscles require ATP
Myosin breaks down ATP
Sustained exercise
Requires cellular respiration
Regenerates ATP

41. Cells alive muscle clip

42. Metabolic Pool: Catabolism (1)
Foods:
Sources of energy rich molecules
Carbohydrates, fats, and proteins
Catabolism (breakdown side of metabolism)
Breakdown products enter into respiratory pathways as intermediates
Carbohydrates
Converted into glucose
Processed as above

43. The Metabolic Pool Concept

44. Metabolic Pool: Catabolism (2)
Breakdown products enter into respiratory pathways as intermediates (cont.)
Proteins
Broken into amino acids (AAs)
Some AAs used to make other proteins
Excess AAs deaminated (NH2 removed) in liver
Results in poisonous ammonia (NH3)
Quickly converted to urea
Different R-groups from AAs processed differently
Fragments enter respiratory pathways at many different points

45. Metabolic Pool: Anabolism (1)
All metabolic reactions part of metabolic pool
Intermediates from respiratory pathways can be used for anabolism
Anabolism (build-up side of metabolism):
Carbs:
Start with acetyl-CoA
Basically reverses glycolysis (but different pathway)
Fats
G3P converted to glycerol
Acetyls connected in pairs to form fatty acids
Note – dietary carbohydrate RARELY converted to fat in humans!

46. Metabolic Pool: Anabolism (2)
Anabolism (cont.):
Proteins:
Made up of combinations of 20 different amino acids
Some amino acids (11) can be synthesized from respiratory intermediates
organic acids in citric acid cycle can make amino acids
Add NH2 – transamination
However, other amino acids (9) cannot be synthesized by humans
Essential amino acids
Must be present in diet or die

47. Review Glycolysis Transition Reaction Citric Acid Cycle
Electron Transport System
Fermentation
Metabolic Pool
Catabolism
Anabolism