The main web site for Dental Biochemistry is at:

http://dentalbioc.uthscsa.edu/

Since you’ve all had biochemistry before:

you should recognize about 2/3 of the material as material you’ve had before.

About 1/3 of the material consists of applying basic biochemistry to understanding understanding biological processes of relevance to your profession.

Your overall objective is to link the basic material to the applied material.

Caries

Fibrous proteins

Connective tissue

Immunoglobulins

Inflammation

Blood clotting

Drug resistance

Hemoglobin

Taste

Hormones

Bones and teeth

Nutrition

Diabetes

Cancer

pH

Carbohydrates

Amino acids

Proteins

Enzymes

Lipids

Membranes

Glycolysis

TCA cycle

Ox. Phos.

Pentose phosphate

Gluconeogenesis

Glycogen

Urea cycle

AA metabolism

Nucleotide metabolsim

Lipid metabolism

Replication

Transcription

Translation

Biomolecules Pathways Physiological processes

Micrograph of a white spot lesion

Erosion is sub-surface. Surface layer is yet to break through.

Summary of processes involved in caries

Ca10(OH)2(PO4)6

Ca10(OH)2(PO4)6

Stephan's Curve showing readings from a pH meter on the surface of enamel under plaque.

Critical pH=5.5

pH and Tooth Decay• Tooth enamel is 96% mineral.• The mineral is primarily hydroxyapatite.• Hydroxyapatite is crystalline calcium

phosphate.• Calcium phosphate is more soluble when the

pH decreases (especially below 5.5):Ca10(PO4)6(OH)2 + 8H+ → 10Ca2+ + 6HPO4

2- + 2H2O

• Some bacteria produce lactic acid when they metabolize sugars anaerobically.

• Lactic acid produced by tooth-attached bacteria initiates most tooth decay by dissolving the mineral of enamel.

Phosphate and Bicarbonate are the MajorBuffers in Saliva

------------------------------------------------------------------------------------------Salivary Composition in Normal Adults------------------------------------------------------------------------------------------

Parotid Submandibular PlasmapH 6.8-7.2 6.8-7.2 7.35Flow Rate 0.7 0.6(mL/min/gland)

millimoles per literPotassium 20 17 4Sodium 23 21 140Chloride 23 21 105Bicarbonate 20 18 27Calcium 2 3.6 5Magnesium 0.2 0.3 2Phosphate 6 4.5 2 pKa2= 7.2

pKa1= 6.1

Weak Acids as Buffers

The titration curves of all monoprotic, weak acids have the same shape. The midpoint is at a pH value equal to the pKa value.

plaque

pellicleenamel

Summary

The objective is to envision your basic biochemical principles in the act of explaining how certain physiologic situations come about.

Professors teaching the principles will help you out by interjecting some examples of the principles in action.

Professors teaching about the physiologic situations will help you out by mentioning some of the principles at work.

We will put some lectures about physiologic situations up front to establish what sorts of overall processes you are trying to understand.

You can help yourself out by seeking as many connections as possible.

Exemption Exam

There is an exemption exam on July 25.

If you can answer 80/100 multiple choice questions, you can exempt the course.

To prepare for the exemption exam:

Caries

Fibrous proteins

Connective tissue

Immunoglobulins

Inflammation

Blood clotting

Drug resistance

Hemoglobin

Taste

Hormones

Bones and teeth

Nutrition

Diabetes

Introduction

pH

Carbohydrates

Amino acids

Proteins

Enzymes

Lipids

Membranes

Replication

Transcription

Translation

Intro. metabolism

Glycolysis

TCA cycle

Ox. Phos.

Pentose phosphate

Gluconeogenesis

Glycogen

Urea cycle

AA metabolism

Nucleotide metabolsim

Lipid metabolism

Read this stuff first

Caries

Fibrous proteins

Connective tissue

Immunoglobulins

Inflammation

Blood clotting

Drug resistance

Hemoglobin

Taste

Hormones

Bones and teeth

Nutrition

Diabetes

Introduction

pH

Carbohydrates

Amino acids

Proteins

Enzymes

Lipids

Membranes

Replication

Transcription

Translation

Intro. metabolism

Glycolysis

TCA cycle

Ox. Phos.

Pentose phosphate

Gluconeogenesis

Glycogen

Urea cycle

AA metabolism

Nucleotide metabolsim

Lipid metabolism

Then ask how this stuff clarifies that stuff.

Test yourself using 2nd half of final exam from previous years.