Introduction to Introduction to BiochemistryBiochemistry

BiochemistryBiochemistry

Chemistry of living organisms.The study of biology at the molecular level.

ElementsElements

• Make up all matter.• 92 occur in nature.• Identified by names or chemical symbols

(abbreviations of modern or Latin names).• Identified by number (based on structure of

subunits or atoms).• Described and organized in periodic table.

Periodic TablePeriodic Table

AtomsAtoms• Subunits of elements.• Smallest complete units of matter.• Cannot be broken down or changed by

ordinary chemical and physical means.

facstaff.gpc.edu

Atomic StructureAtomic StructureNucleus

– Positively charged protons.– Neutrally charged neutrons.– Surrounded by negatively charged electrons.

www.bartleby.com

Molecules and CompoundsMolecules and Compounds

Molecules• Formed when two or more atoms unite on

the basis of their electron structures• Can be made of like atoms or atoms of

different elements

Compounds• Composed of two or more elements

BiomoleculesBiomolecules Carbohydrates Lipids Proteins Nucleic acid

CarbohydratesCarbohydrates

Composed of carbon, hydrogen, and oxygen. Sugars Monosaccharides

– Ex. Glucose Disaccharides

– Ex. Sucrose Polysaccharides

– Ex. Glycogen, Peptidoglycan

Carbohydrate - GlucoseCarbohydrate - Glucose

www.palaeos.com

Carbohydrate - SucroseCarbohydrate - Sucrose

www.chm.bris.ac.uk

Carbohydrate - PeptidoglycanCarbohydrate - Peptidoglycan

www.biologie.uni-hamburg.de

Carbohydrate - GlycogenCarbohydrate - Glycogen

www.elmhurst.edu

LipidsLipidsFatty Acids

– The building blocks of lipids.

biology.clc.uc.edu

courses.cm.utexas.edu

LipidsLipidsExamples are:

– Waxes– Fats and oils– Phospholipids– Steroids

Phospholipid Cell Membrane. www.williamsclass.com

ProteinsProteins

Made up of polymers of amino acids.

“beads on a string.” 20 primary amino

acids exist. A polymer of 3 or

more amino acids forms a polypeptide.

ProteinsProteins

Primary Structure– Linear sequence of amino acids.

Secondary Structure– Form helices or sheets due to their structure.

Tertiary Structure– A folded protein.

Quaternary Structure– 2 or more polypeptide chains bonded together.

Protein StructureProtein Structure

www.denizyuret.com

EnzymesEnzymes Are proteins. Are considered

biological catalysts.– Speed up a chemical

reaction without being altered.

Names often end in “-ase.”– Ex. Lipase,

carbohydrase. Act on a substrate. Proteins, including

enzymes, can be denatured.

Nucleic AcidsNucleic Acids

DNA and RNA.– (DNA - deoxyribonucleic acid,

RNA - ribonucleic acid).Is the “hereditary molecule.”Contains genes that code for a certain

product.DNA is translated into RNA which is used

to produce a protein or other product.

Nucleic Acid StructureNucleic Acid Structure

DNA nucleotides– Building blocks of DNA.

RNA nucleotides– Building blocks of RNA.

Nucleic Acid StructureNucleic Acid Structure

DNA– Nitrogenous base– Deoxyribose– Phosphate group

RNA– Nitrogenous base– Ribose– Phosphate group

www.microbelibrary.org

Nitrogenous BasesNitrogenous Bases

Adenine (A) Guanine (G)Cytosine (C)Thymine (T) – only DNAUracil (U) – only RNA

DNA and RNA

Nitrogenous BasesNitrogenous Bases

A and G – Purines (double-

ring structures)C, T, and U

– Pyrimidines (single-ring structures)

hyperphysics.phy-astr.gsu.edu

DNA StructureDNA Structure Nucleotides bond between

sugar and phosphate groups to form long polymers.

Double-stranded DNA - The two nucleotide

polymers bind at the nitrogenous bases.– Bonding forces cause the

double-stranded polymer to form a double helix.

www.genome.gov

DNA StructureDNA StructureJames Watson (left) and Francis Crick

(right) discovered the double-helix structure of DNA and its process of replication in the 1950s.

www.achievement.org

DNA ReplicationDNA Replication

Occurs during cell division.Both strands of the double-helix unwind

and replicate a complimentary strand.The parent strand and new daughter strand

form a new double-helix.DNA polymerase is one enzyme used in

replication process.

DNA Replication – DNA Replication – Semiconservative ReplicationSemiconservative Replication

courses.cm.utexas.edu

Gene ExpressionGene Expression

A gene contains the instructions for making a gene product.

The genetic code is based on the sequence of the nitrogenous bases (A, T, C, and G).

The gene product is usually a protein but may be different types of RNA.

The Central DogmaThe Central Dogma

Proposed by Francis Crick in 1957.Explains the flow of genetic information

within a cell.DNA RNA Protein

The Central DogmaThe Central Dogma

1. Genetic information contained in one gene of DNA molecule is used to make one molecule of mRNA by a process called transcription.– mRNA (messenger RNA) is one of 3 types of RNA

used in protein synthesis.2. The genetic information in the mRNA

molecule is used to make a protein in a process called translation.

TranscriptionTranscription

The genetic code from the DNA molecule is transcribed to produce an mRNA molecule.

trc.ucdavis.edu

TranslationTranslationThe process of translating the mRNA

sequence, which directs the proper sequence of amino acids to produce a particular protein or product.

www.scq.ubc.ca

The EndThe End