1. (a) Chemical level: a molecule in
the membrane that encloses a cell
(b) Cellular level: a cell
in the stomach lining
(c) Tissue level: layers of
tissue in the stomach wall
(d) Organ level:
the stomach
(e) Body system
level: the digestive
system
(f) Organism level

2. Recall basic cell physiology
This class I will assume you know the basic functions of these structures:
Smooth and rough endoplasmic reticulum
Golgi
Peroxisomes
Lysosomes
Mitochondria
Basic structure of the plasma membrane

3. Gazing into a cell…. Golgi Nucleus Rough ER Smooth ER Peroxisome
Lysosome
Smooth ER
Mitochondria
Golgi

4. Cristae
Inner membrane
Outer
membrane

6. Glycolysis can occur with or without oxygen
Yet, aerobic respiration yields more energy from glucose and occurs in the mitochondria

7. Chemical reactions for energy
Citric acid cycle
Glycolysis
Electron transport chain
Cytosol

8. First, glycolysis – then either:
Making ATP
First, glycolysis – then either:
Aerobic Pathway
Citric acid cycle
Electron transport chain
Anaerobic Pathway
Fermentation

9. Within the mitochondria...
Pyruvate enters mitochondria
Citric Acid Cycle
matrix
Electron Transport
Inner membrane (cristae)

10. Pyruvate
Acetyl-CoA
Citric Acid
(or Krebs)
Cycle
CO2
CO2
ATP

11. Where does weight ‘go’ when someone loses weight?

12. Electron Transport Chain
High energy electrons taken from hydrogen are transferred through a series of carriers on inner membrane
ATP Synthase w/in cristae
32 ATP formed

13. Free radicals from ETC
A by-product of ETC is the production of abnormal versions of O2 (O2-, O2--)
These molecules are highly reactive and produce “free radicals”, which contribute to aging and some diseases.

15. Energy Harvest
Glycolysis (from one glucose) 2 ATP 2 NADH (makes 4 ATP in ETC) Citric Acid Cycle 2 ATP plus NADH, FADH2 for ETC Electron Transport Chain 28 ATP by oxidative phosphorylation

16. Anaerobic conditions
Aerobic conditions

17. Lactic acid myth
Lactic acid (really lactate) isn’t the cause of muscle fatigue and soreness Lactate leaves muscle, enters blood and is used elsewhere for ATP production (using O2)

18. Lactate threshold
Interval training uses periods of training above and below the L threshold. High intensity portions stimulate your body to produce enzymes that speed the use of lactate fuel (MCT1 carrier protein)

19. Plasma membrane of cells

20. EXTRACELLULAR ENVIRONMENT
oligosaccharide
groups
phospholipid
cholesterol
EXTRACELLULAR ENVIRONMENT
(cytoskeletal
proteins beneath
the plasma
membrane)
open
channel
protein
gated
(open)
(closed)
active
transport
RECEPTOR
PROTEIN
RECOGNITION
PROTEIN
ADHESION
PROTEIN
TRANSPORT
PROTEINS
CYTOPLASM
Receptor sites (ex: endocrine sites)
Cell adhesion (CAM) grips neighbor cell
Channels for ions, small molecules
Carrier proteins
Attach to cytoskeleton

21. Membrane receptors Binding to the receptor will:
Open or close channels for ions (Na+, K+, Ca++)
Transfer a signal to 2nd messenger to trigger events in the cell

22. 2nd messenger system
will activate an enzyme

23. Other cell adhesions
Extracellular matrix - Biological “glue.” 3 protein fibers are interwoven in this matrix: collagen, elastin, fibronectin. Secreted by cells Desmosomes – “Rivets” to anchor adjacent cells that are not touching

24. Other cell adhesions
Tight junctions – Epithelium cells form tight seal at points of contact Gap junctions - Small tunnels connect cells

25. open channel
proteins
gated channel
proteins
transport protein

26. Passive transport (facilitated diffusion)
transport protein with binding site for
a specific substance (the solute)
Passive
transport
(facilitated
diffusion)
protein has 2 different
conformations

27. Active Transport phosphorylation required Concentration gradient
high solute concentration
Concentration
gradient
Active
Transport
phosphorylation
required
Direction
of transport

28. concentrations now equal
Membrane (permeable to water only)
Side 1
Side 2
Solute can’t move to
side 1 down its gradient
but water moves
H2O
Side 1
Side 2
Water and solute
concentrations now equal

29. Osmosis is balanced by hydrostatic pressure
Membrane (permeable to H2O)
Side 1
Side 2
Solute can’t move to
side 1 down its gradient
H2O
Pure water
Gradients still exist
Osmosis is balanced by hydrostatic pressure
Side 1
Side 2
Hydrostatic
(fluid)
pressure
difference
Osmosis
Hydrostatic
pressure

30. Isotonic
Hypotonic
Hypertonic