1. Unit 1.5 Biochemistry Review Chapter 2 in text book

2. Biochemistry is: The Chemistry of Life
the study of the molecules that compose living organisms and how they work to maintain life.
carbohydrates, fats, proteins, and nucleic acids

3. Elements in our body

4. Minerals in our body
Inorganic elements extracted from soil by plants and passed up the food chain to humans
Ca, P, Cl, Mg, K, Na, I, Fe, Zn, Cu, and S
constitute about 4% of body weight
structure (teeth, bones, etc)
enzymes

6. Molecules and Chemical Bonds
Molecules—covalent bonds(C6H12O6)
composed of two or more
atoms (can be same)united by a covalent
chemical bond. These dissolve in water but do not dissociate.
Compounds—ionic bonds (NaCl)
composed of two or more different elements bonded together by an ionic bond. These dissociate in water.

7. Covalent Bonds Formed by sharing electrons Relatively strong
Not dissociating in water (usually)
Are present in most Organic Molecules!

8. Ionic Bonds electron donated by one element and received by the other
Relatively weak attraction that is easily disrupted in water, as when salt dissolves
Are found in most inorganic compounds.

9. The beauty of water and its Hydrogen Bonds
Hydrogen bond – a weak attraction between a slightly positive hydrogen atom in one molecule and a slightly negative oxygen or nitrogen atom in another.
Water molecules are weakly attracted to each other by hydrogen bonds
relatively weak bonds
very important to physiology
protein structure
DNA structure

10. Water
Water’s polar covalent bonds and its V-shaped molecule gives water a set of properties that account for its ability to support life.
solvency
cohesion
adhesion
chemical reactivity
thermal stability
Virtually all metabolic reactions depend on the solvency of water

11. Hydrogen Bonding in Water
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. H O H H O H O H H O H
Covalent bond H
Figure 2.8
Hydrogen bond O
Water molecule H H

12. Water in our body
Most mixtures in our bodies consist of chemicals dissolved or suspended in water
Water 50-75% of body weight
depends on age, sex, fat content, etc.

13. Thermal Stability of Water helps maintain homeostasis!
Water helps stabilize the internal temperature of the body
has high heat capacity – the amount of heat required to raise the temperature of 1 g of a substance by 1 degree C.
calorie (cal) – the amount of heat that raises the temperature of 1 g of water 1 degree C.
hydrogen bonds inhibit temperature increases by inhibiting molecular motion
water absorbs heat without changing temperature very much

14. Energy and Chemical Rnx
All Chemical reactions either produce (store) or take energy: Are exothermic or endothermic 
In the body, ALL chemical reactions are collectively called your METABOLISM
There are 2 kinds of metabolic reactions

15. Kinds of Reactions Catabolism Anabolism Decomposition and Synthesis
Break down and build up
Adds H2O and removes H2O
Hydrolysis and Dehydration
Digestion

17. Metabolism All the chemical reactions of the body
Catabolism (takes H2O)
energy releasing (exergonic) decomposition reactions
Hydrolysis
breaks bonds
produces smaller molecules
releases useful energy
Anabolism (produces H2O)
energy storing (endergonic) synthesis reactions
Dehydration
requires energy input
production of protein or fat
driven by energy that catabolism releases

18. Hydrolysis
Splitting a polymer (lysis) by the addition of a water molecule (hydro)
a covalent bond is broken
All digestion reactions consists of hydrolysis reactions
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Dimer
Monomer 1
Monomer 2 O OH HO
H2O H+ +
OH–
(b) Hydrolysis
Figure 2.15b

19. Dehydration Synthesis
Monomers covalently bond together to form a polymer with the removal of a water molecule
A hydroxyl group is removed from one monomer and a hydrogen from the next
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Dimer
Monomer 1
Monomer 2 O OH HO H+ +
OH–
H2O
(a) Dehydration synthesis
Figure 2.15a

20. Reaction Rates Reaction Rates affected by: concentration temperature
reaction rates increase when the reactants are more concentrated
temperature
reaction rates increase when the temperature rises
catalysts –substances that temporarily bond to reactants, hold them in favorable position to react with each other, and may change the shapes of reactants in ways that make them more likely to react.
speed up reactions without permanent change to itself
holds reactant molecules in correct orientation
catalyst not permanently consumed or changed by the reaction
Enzymes – most important biological catalysts

21. In Physiology, the chemistry of metabolism is called: Organic Chemistry
Study of compounds containing carbon
4 categories of carbon compounds
carbohydrates
lipids
proteins
nucleotides and nucleic acids

22. Protiens RUN OUR LIFE 5. Recognition and Protection
Proteins are a very diverse macromolecule and perform many functions within our body!!
1. Provide Structure
EX: Keratin and Collagen
2. Carry our Communication
Ex: hormones, cell to cell signals, receptors, & reversibly
binding proteins called, Ligands
3. Membrane Transport
EX: protein channels in PM, carriers that bind solutes,
trigger nerve and muscle activity
4. Catalysis ENZYMES
5. Recognition and Protection
EX: Glycoproteins in immune function, Antibodies, Clotting
proteins

23. Enzymes as catalysts!
Enzymes - proteins that function as biological catalysts
permit reactions to occur rapidly at normal body temperature
Substrate - substance an enzyme acts upon
Lowers activation energy (energy needed to get reaction started) and push reactions involving substrates to go faster (with more energy, more completely)
Enzymes can help build substrates together or help break substrates apart.

24. Enzymes and Activation Energy
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Activation
energy
Activation
energy
Net
energy
released by
reaction
Net
energy
released by
reaction
Energy level
Free energy content
of reactants
Energy level
of products
Time
Time
(a) Reaction occurring without a catalyst
(b) Reaction occurring with a catalyst
Figure 2.26a, b

25. They PUSH molecules together They PULL molecules apart
Enzymes do not get consumed in the Reaction!! They are available for re-use !!
Astonishing speed
one enzyme molecule can consume millions of substrate molecules per minute
They PUSH molecules together
They PULL molecules apart
Sometimes enzymes have “helpers” called:
Cofactors (iron, copper, zinc, mg, ca) these cofactors stimulate proper folding
Coenzymes (NAD+)….electron acceptors that carry electrons from various metabolic pathways to others.

27. Factors that change enzyme shape
pH and temperature
alters or destroys the ability of the enzyme to bind to substrate
enzymes vary in optimum pH
salivary amylase works best at pH 7.0
pepsin works best at pH 2.0
temperature optimum for human enzymes – body temperature (37 degrees C)

28. Q????
Think about enzymes and now why do you think it is extremely important for you body to maintain homeostasis?

29. Nucleotides
Energy converting molecule

30. Adenosine Triphosphate (ATP)
body’s most important energy-transfer molecule
briefly stores energy gained from exergonic reactions
releases it within seconds for physiological work
holds energy in covalent bonds
2nd and 3rd phosphate groups have high energy bonds ~
most energy transfers to and from ATP involve adding or removing the 3rd phosphate

31. Sources and Uses of ATP Figure 2.30 are converted to Glucose + 6 O2
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are converted to
Glucose O2
6 CO H2O
which releases
energy
which is used for
ADP + Pi
ATP
which is then available for
Muscle contraction
Ciliary beating
Active transport
Synthesis reactions
etc.
Figure 2.30

32. Overview of ATP Production
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Glycolysis
Glucose 2
ADP + 2 Pi 2
ATP
Pyruvic acid
Anaerobic
fermentation
Stages of glucose oxidation
No oxygen
available
Figure 2.31
Lactic acid
Aerobic
respiration
Oxygen
available
CO2 + H2O
Mitochondrion 36
ADP + 36 Pi 3 6
ATP
ATP consumed within 60 seconds of formation
entire amount of ATP in the body would support life for less than 1 minute if it were not continually replenished
cyanide halts ATP synthesis

33. Other Nucleotides Guanosine triphosphate (GTP)
another nucleotide involved in energy transfer
donates phosphate group to other molecules
Cyclic adenosine monophosphate (cAMP)
nucleotide formed by removal of both second and third phosphate groups from ATP
formation triggered by hormone binding to cell surface
cAMP becomes “second messenger” within cell
activates metabolic effects inside cell