vander’s human physiology the mechanisms of body function and the metabolic pathways chapter 3
TRANSCRIPT
![Page 1: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/1.jpg)
Vander’s Human Physiology
The Mechanisms of Body Function and The Metabolic Pathways
Chapter 3
![Page 2: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/2.jpg)
• Structure determines function.
• That which alters structure alters function.
• Cells:
membranes─internal and external partitions
nucleus─genomic DNA
ribosomes─protein synthesis
endoplasmic reticulum─synthesis and calcium dynamics
Golgi apparatus─secreted proteins
mitochondria─ATP synthesis
miscellaneous organelles
Chapter 3Cell structure and protein function
![Page 3: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/3.jpg)
• Central dogma: genes to proteins
transcription (DNA to RNA) splicing (RNA to mRNA) translation (mRNA code determines amino acid sequence in protein synthesis)
• ATP/chemical energy: substrate/oxidative phosphorylation
• Enzymes and metabolic pathways
Chapter 3Cell structure and protein function (cont.)
![Page 4: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/4.jpg)
Sizes, on a log scale.
Figure 3-2
![Page 5: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/5.jpg)
Electron Micrograph of organelles in a hepatocyte (liver cell).
Figure 3-3
![Page 6: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/6.jpg)
Organelles have their own membranes.
Figure 3-4
![Page 7: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/7.jpg)
Electron micrograph and sketch of plasma membrane
surrounding a human red blood cell.
Figure 3-6
![Page 8: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/8.jpg)
Ph
osp
ho
lip
id b
ilay
er
Figure 3-7
![Page 9: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/9.jpg)
Cir
cle
s r
ep
res
en
t a
min
o a
cid
s in
th
e li
nea
r s
equ
en
ce
of
the
pro
tein
Schematic cartoon of a transmembrane protein.
Th
e a
min
o a
cid
s a
lon
g
the
me
mb
ran
e s
ecti
on
are
like
ly t
o h
ave
no
n-p
ola
r s
ide
ch
ain
s
Figure 3-8
![Page 10: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/10.jpg)
Drawing of the fluid-mosaic model of membranes, showing the phospholipid bilayer and imbedded proteins.
Figure 3-9
![Page 11: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/11.jpg)
Desmosomes provide strong attachments.
Figure 3-10a
![Page 12: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/12.jpg)
Tight junctions prevent leaks.
Figure 3-10b
![Page 13: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/13.jpg)
Gap junctions communicate and coordinate.
Figure 3-10d
![Page 14: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/14.jpg)
{genomic DNA}
{site of ribosome assembly}
Figure 3-11
![Page 15: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/15.jpg)
Figure 3-12
![Page 16: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/16.jpg)
Figure 3-13
![Page 17: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/17.jpg)
Figure 3-14
![Page 18: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/18.jpg)
Protein filaments function in movement and support.
Figure 3-15
![Page 19: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/19.jpg)
NUCLEUS
The DNA code is “transcribed” into mRNA.
RIBOSOMES
The mRNA is “translated” to give instructions for proteins synthesis.
Figure 3-16
![Page 20: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/20.jpg)
GENES “CODE FOR” PROTEINS
The “triplet code” of DNA determineswhich amino acid will be placed in
each position of the protein.
(note: mRNA intermediate not shown)
Figure 3-17
![Page 21: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/21.jpg)
Transcription of a gene from the DNA templateto RNA transcript. [RNA triplets are called “codons.”]
Figure 3-18
![Page 22: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/22.jpg)
Introns stay “in” the nucleus;exons “exit” the nucleus.Figure 3-19
![Page 23: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/23.jpg)
Codon sequence on mRNA pairs with anticodon oftRNA to determinewhich amino acidgets put into the new protein.
Figure 3-20
![Page 24: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/24.jpg)
Arrow indicates movement of the ribosome along the mRNA.Figure 3-21
![Page 25: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/25.jpg)
An mRNA molecule may haveseveral ribosomes on it.
Figure 3-22
![Page 26: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/26.jpg)
Large proteins can be cut
into smaller proteins.
Figure 3-23
![Page 27: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/27.jpg)
Transcription is precisely regulated.
Figure 3-24
![Page 28: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/28.jpg)
Figure 3-25
… from mRNA
to secreted
protein …
![Page 29: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/29.jpg)
Shape and charge
work togetherin matching up ligands with their receptors.
Figure 3-26
![Page 30: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/30.jpg)
The shape and charge distribution of a binding protein determine which ligands it will bind.
Figure 3-27
The amino-acid sequence
of a protein determines
both shape and the distribution of
charge.
ligand
binding protein
![Page 31: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/31.jpg)
Protein Xbinds a wider
diversity of ligandsthan doesProtein Y.
Protein Yhas
greaterligand-
specificity than
Protein X.
Figure 3-28
![Page 32: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/32.jpg)
Protein 1 has the best ligand fit in terms of both shape and charge, so, of these three proteins, it has the greatest affinity for this ligand.
Figure 3-29
![Page 33: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/33.jpg)
Figure 3-30
Saturation occurs when ligands become so abundant that every binding site is occupied.
![Page 34: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/34.jpg)
When two proteins can bind the same ligand,saturation occurs more readily for the protein that has a higher affinity (Protein Y, here) for the ligand.
Figure 3-31
![Page 35: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/35.jpg)
Figure 3-32
An allostericmodulatorforms a non-covalent bondwith theprotein.
A covalent modulator forms acovalent bond with the protein.
![Page 36: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/36.jpg)
For the reversible reaction:
A + B C + Dthe law of mass action applies,meaning that an increase in the
amount of reactants will increase the rate of product formation, i.e.,
A + B C + DAlternatively, an increase in the
the amount of products will decrease the rate of product formation. i.e.,
A + B C + D
![Page 37: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/37.jpg)
Enzymes accelerate the reactions they catalyze byusing binding sites to bring substrates together.
Figure 3-33
![Page 38: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/38.jpg)
Saturation of enzymes occurs when substrates become so abundant that all enzymes are participating fully.
Figure 3-34
![Page 39: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/39.jpg)
Increasing the availability of enzymesresults in an increased rate of reaction.
Figure 3-35
![Page 40: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/40.jpg)
An allosteric or covalent modulator that increases an enzyme’s affinity for its substrates will increase the rate of product formation.
Figure 3-36
![Page 41: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/41.jpg)
Any given enzyme can have a diversity ofallosteric and/or covalent modulation sites.
Figure 3-37
![Page 42: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/42.jpg)
The amount of enzyme and its allosteric and/or covalent inhibitors/activators determine the rate of product formation.
Figure 3-38
![Page 43: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/43.jpg)
E, the “end-product,” acts as an inhibitory modulator
of enzyme e2, the rate-limiting enzyme in this sequence.
Figure 3-39
![Page 44: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/44.jpg)
Breaking down
fuels
provides chemical energy
to rebuild ATP supplies.
Figure 3-40
![Page 45: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/45.jpg)
![Page 46: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/46.jpg)
Glycolysis: A net gain of 2molecules of ATP and 4 atomsof hydrogen.
Figure 3-41
![Page 47: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/47.jpg)
Anaerobic conditions can occurin periods of high energy demand;lactate lactic acid is formed, increasing acidity in the tissue.Figure 3-42
![Page 48: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/48.jpg)
Each transition of pyruvate to acetyl coenzyme A yields one NADH and one CO2. The acetyl coenzyme A then enters the Krebs cycle.
Figure 3-43
![Page 49: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/49.jpg)
In aerobic conditions,two spins of the Krebs cycle occur for each glucose that enters glycolysis.
Figure 3-44
![Page 50: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/50.jpg)
For each NADH, 3 ATPs are formed.For each FADH2, 2 ATPs are formed.
Figure 3-45
![Page 51: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/51.jpg)
Glucose catabolism “powers” ATP synthesis via a combination of substrate and oxidative phosphorylation.Figure 3-46
![Page 52: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/52.jpg)
Glycogen is a storage polymer of glucose.When fed, “glycogenesis” occurs (up arrows).When fasted, “glycogenolysis” occurs (down arrows).
Figure 3-47
![Page 53: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/53.jpg)
Glucose catabolismoccurs in most cells(black arrows).
During fasting, theliver synthesizesglucose (= gluconeogenesis; red arrows).
This new glucose isneeded in the central nervous system.
Figure 3-48
![Page 54: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/54.jpg)
![Page 55: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/55.jpg)
Figure 3-49
The catabolism of the many covalent bonds in fatty acids that occurs inmitochondria.
![Page 56: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/56.jpg)
Amino acids are used as fuels after removal of the amino group.
One amino acid can be converted to another amino acidby altering the position of some of the atoms.
Figure 3-50
![Page 57: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/57.jpg)
Figure 3-51
Transaminationand deaminationroutes by whichthe amino acidsalanine and glutamic acid contribute to energy metabolism.
![Page 58: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/58.jpg)
Consideration of the inputs and outputs of the body’s overall pool of amino acids
Figure 3-52
![Page 59: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/59.jpg)
Figure 3-53
Inter-conversions of the molecules thatserve as building blocks and as fuels.
![Page 60: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/60.jpg)
![Page 61: Vander’s Human Physiology The Mechanisms of Body Function and The Metabolic Pathways Chapter 3](https://reader035.vdocuments.us/reader035/viewer/2022081515/56649dde5503460f94ad7818/html5/thumbnails/61.jpg)
The End.