Suzanne D'Anna1 Biochemistry The Chemical Composition of Living Matter

Suzanne D'Anna2 Two principal Classes of Compounds Found in the Body l organic compounds l inorganic compounds

Suzanne D'Anna3 Organic Compounds l contain carbon and hydrogen - carbon is a unique element because it has 4 electrons in valence shell enabling it to combine with many different atoms - large, covalently bonded molecules l Examples: - carbohydrates, proteins, nucleic acids

Suzanne D'Anna4 Inorganic Compounds l lack hydocarbons l smaller simpler molecules l Examples: - water, oxygen, carbon dioxide salts, some acids and bases

Suzanne D'Anna5 Water l most important - 2/3 body weight Why is water so vital? l high heat capacity l excellent solvent l important reactant l lubricant l protective l transportation

Suzanne D'Anna6 Salt l most plentiful body salts contain calcium and phosphorus l found mostly in bone and teeth l ions of salts provide essential chemical elements l Example: - ionic calcium (Ca ++ ) - essential for nerve impulses

Suzanne D'Anna7 Acids l electrolytes l compounds which ionize and dissociate in H 2 0 liberating hydrogen ions (H + ) l conduct electrical current l sour taste l dissolve and burn

Suzanne D'Anna8 Bases l electrolytes l any molecule which can combine with hydrogen ions l proton (H+) acceptors l help maintain stable pH of body fluids l bitter taste, feel slippery l Example: - sodium bicarbonate

Suzanne D'Anna9 pH Scale l based on the number of hydrogen ions is solution l measure of acid or base level l acid l base l at pH 7 hydrogen and hydroxyl ions are equal (neutral)

Suzanne D'Anna10 pH scale increasingly acidic neutral (7) increasingly basic (alkaline)

Suzanne D'Anna Lemon juice, gastric juice (pH 2) 3 4 Tomato juice (pH 4.2) 5 6 Urine pH 5-8, saliva, milk (pH 6.5) 7 Distilled water (H 7), Human blood; semen (pH 7.4) 8 Egg white (pH 8) 9 10 Milk of magnesia (pH 10.5) Ammonia (pH ) basic acidic The pH scale

Suzanne D'Anna12 Organic Compounds l contain carbon and hydrogen l carbon molecules react with many other carbon atoms to form large chains and rings with different molecules l 2-3% of total body weight

Suzanne D'Anna13 Carbohydrates l are sugars or starches l provide most of the energy used by cells l some carbohydrates are converted into other substances which are used to build structures and to generate ATP. l if not used immediately for ATP synthesis carbohydrates are converted into fat or glycogen

Suzanne D'Anna14 Carbohydrates (cont.) l monosaccharides - simple sugar - glucose, fructose, galactose l disaccharides - double sugar - maltose, sucrose, and lactose l polysaccharides - many sugars - glycogen, hyaluronic acid, (provides for energy for sperm) and condroitin sulfate

Suzanne D'Anna15 ATP (adenosine triphosphate) l provides chemical energy l necessary for life processes l energy is released as glucose and stored in bonds of ATP l when bonds are broken down (hydrolysis) energy can then be used

Suzanne D'Anna16 Lipids l organic compounds l 18%-25% of body weight l fewer covalent bonds l most are insoluble in H 2 O l fat-marbled meats, egg yolks, milk, oils

Suzanne D'Anna17 Lipids (cont.) l neutral fats (triglycerides) - most common in the body - all excess food is converted into triglycerides and stored in fat cells (adipose tissue) as an energy source - adipose tissue insulates and protects organs

Suzanne D'Anna18 Lipids (cont.) l phospholipids (compound lipids) - contain phosphorus - interact with H 2 O - major component of cell membranes - help in transport of lipids in plasma - found in high concentrations in nerves and brain tissue

Suzanne D'Anna19 Lipids (cont.) l steroids - cholesterol is most important molecule in steroids - sex hormones, cortisol, bile salts, and vitamin D

Suzanne D'Anna20 Proteins l complex in structure l composed of amino acids l larger range of functions than carbohydrates and lipids l normal lean adult is % proteins

Suzanne D'Anna21 Functions of Proteins l structural - collagen fibers are found in connective tissues, keratin is in hair and skin l regulatory - many hormones that regulate are proteins l contractile - actin and myosin are protein filaments found in all muscle cells

Suzanne D'Anna22 Functions of Proteins (cont.) l immunological - antibodies are proteins l transport - hemoglobin carries oxygen and carbon dioxide, lipoproteins carry lipids l catalytic - enzymes alter rate of reactions

Suzanne D'Anna23 Functional Proteins l antibodies - bind with and inactivate bacteria, toxins, and viruses - function in immune response - help protect body from foreign substances

Suzanne D'Anna24 Functional Proteins (cont.) l hormones - help regulate growth and development - insulin - regulates blood sugar levels - guide neuron growth

Suzanne D'Anna25 Functional Proteins (cont.) l transport proteins - hemoglobin transport of oxygen in blood - iron transport

Suzanne D'Anna26 Functional Proteins (cont.) l contractile proteins - aid in muscle contraction and body movement - aid in cell division, movement and sperm propulsion toward the egg

Suzanne D'Anna27 Functional Proteins (cont.) l catalyst (enzymes) - essential to almost every biochemical reaction in the body - increase rate of chemical reactions

Suzanne D'Anna28 Nucleic Acids

Suzanne D'Anna29 Nucleic Acids l make up genes which provide blueprint for life l determine organism type l direct growth and development l dictate protein structure l composed of C, O, H, N, and Ph l largest biological molecules in the body

Suzanne D'Anna30 Nucleotides l nucleotides are building blocks (monomers) of nucleic acids formed by C,O,H,N, and P, which are bound together l Three main parts: - nitrogenous base (organic base) - a phosphate group - a five-carbon sugar (ribose or deoxyribose)

Suzanne D'Anna31 Two Major Types of Nucleic Acids l DNA (deoxyribonucleic acid) l RNA (ribonucleic acid)

Suzanne D'Anna32 DNA (deoxyribonucleic acid) l genetic material found in cell nucleus l replicates self before cell divides ensuring genetic material in every cell is identical l provides instruction for every protein building block in the body

Suzanne D'Anna33 DNA (cont.) l long double chain of nucleotides l held together by hydrogen bonds l ladder-like molecule l entire molecule is coiled into a spiral structure called a double helix

Suzanne D'Anna34 DNA

Suzanne D'Anna35 RNA (ribonucleic acid) l located outside nucleus l single nucleotide strand l carries out orders of DNA l three types of RNA - messenger RNA (mRNA) - transfer RNA (tRNA) - ribosomal RNA (rRNA)

Suzanne D'Anna36 Messenger RNA (mRNA) l 5% of RNA l carries information from nucleus to the cytosol l it is used as template for protein synthesis

Suzanne D'Anna37 Transfer RNA (tRNA) l 15% of RNA l carries specific amino acids to rRNA attached to ribosomes

Suzanne D'Anna38 Ribosomal RNA (rRNA) l 80% of RNA l a component of the ribosomes - ribosomes are structures that are the site of protein synthesis