Carbon Compounds in Cells

What is Organic Chemistry?

• Is the chemistry that deals with element carbon and one or more elements.

• All living organisms are made up of carbon-hints why we study it in biology.

• Examples of organic compounds are:– Protein, Nucleic Acid, Carbohydrates, and

Lipids

• Methane is the simplest organic compound

Carbon Bonding

• Carbon and the other elements are bonded covalently

• Oxygen, hydrogen, Nitrogen, Sulfur and carbon are most abundant elements in living matter

• Carbon can share pairs of electrons with as many as four other atoms to form organic molecules of several configuration

• Much of H and O is linked to form water

Functional Groups

• Are atoms or groups of atoms covalently bonded to a carbon backbone, they covey distinct properties, such as solubility and chemical reactivity, to the complete molecule.

Know P. 38

You will have a quiz on this.

Date: Friday, February 4, 2011

Four Families of Building Blocks

• Simple sugars, fatty acids, amino acids, and nucleotides

• Monomers can be joined to form larger polymers.

• Enzymes-is a class proteins that make metabolic reactions proceed faster

Ten Categories of Reactions

• 1- Functional Group transfer from one molecule to another

• 2- Electron transfer- stripped from one one molecule to another

• 3- Rearrangement of internal bond converts one type of organic molecule to another

Continue…• 4- Condensation- two molecules to one

• 5- Cleavage- one molecule into two

• 6- Hydrolysis - break down compounds by adding water

• 7- Dehydration - two components brought together, produces H2O

• 8- Endergonic - requires the input of energy

• 9- Exergonic - releases energy

• 10- Redox - electron transfer reactions

Condensation Reaction

• One molecule is stripped of its H+, another is stripped of its OH-; then the two molecule fragments join to form a new compound and the H+ and OH- form water.

• Example: Starch formed by repeat condensation reaction

Hydrolysis

• Is the reserve: one molecule is split by the addition H+ and OH- (from water) to the components (condensation in reserve)

• Hydrolysis cleave polymer into smaller molecules when required for the building blocks for energy

Carbohydrates: Most Abundant element of life

• Made up of carbon, oxygen and hydrogen in a set proportion of 1:2:1

• Monosaccharides (Simple Sugar)– They are characteristics by solubility in water,

sweet taste, and several –OH• Examples:• Glucose and Fructose: Used assembling larger

carbohydrate

Glucose

Carbohydrates: Continue• Disaccharides: Consists of two monosaccharides

joined together through the process of dehydration synthesis (which removes water in the process)– Examples: Lactose (Glucose + Galactose) Present in Milk

(dehydration synthesis)

– Sucrose (glucose + Fructose) is transported form of sugar used by plants and harvested by humans for use in food

– Continue Examples:– Maltose (two glucose) is present in

germinating seeds

• Pentoses: 5 carbon sugar– Deoxyribose (sugar for DNA)– Ribose (sugar for RNA)

Complex Carbohydrates• Polysaccharides are macromolecules,

polymers with few hundred to a few thousand monosaccharides joined together.– Examples: Starch: Plant storage for energy;

unbranched coil chain and easily hydrolyzed– Cellulose: Found in plants for structure

(insoluble)– Glycogen: (animal cell storage)– Chitin: polymer of glucose (arthropods

exoskeleton)

• Continue Examples– Glycogen: High branched used by animals to

store energy in muscles and liver.• Is also converted to blood sugar when blood sugar

drops

– Chitin: polysaccharide with nitrogen attached to glucose monomers which gives arthropods exoskeleton

Lipids

• A large biological molecules that does not consist of polymers.

• Lipids are greasy or oil compounds with little tendency to dissolve in water (hydrophobic)

• Can be broken down by hydrolysis reaction

• Function: energy storage, membrane structure and coatings

Continue: Lipids

• Fatty Acids– Fatty Acid: is a long chain of mostly carbon

and hydrogen atoms with a –COOH group at one end

Continue..• When they are part of complex lipids, the

fatty acids resemble long flexible tails– Unsaturated fats: fats are liquids (oils) at room

temperature because one ore more double bonds between the carbons in the fatty acids permits “kinks” in the tails

– Example: Fish Oil

Unsaturated Fats

• Saturated fats: (triglycerides) have a single C-C bonds in their fatty acid tails and are solids at room temperature• They are tightly packed together • Solid at room temperature• Examples: Butter and Lard• Diets rich in saturated fat leads to cardiovascular

disease

– Triglycerides: “neutral” fats most abundant lipids and the richest source of energy

Fats

• Are constructed from two kinds of smaller molecules: Glycerol and fatty acids– They are a rich source of energy, yielding

more than twice the energy per weight basis as carbohydrates

– Provides an insulation blanket for animals to endure the harsh cold temperatures

Phospholipids

• Formed from 2 fatty acids + phosphate group attached to glycerol

• Provide structure support in membranes where they are arranged in bilayers

Steroids• Have lipid characteristics by a carbon

skeleton consisting of four fused rings

• Example: Cholesterol: common component of animal cell membranes and is also the precursor from which other steroids are synthesized (Example: vertebrate sex hormones)

Waxes

• They are formed by attachment of long chains of fatty acids to long chains alcohols or carbon rings

• Function: serve as coatings on plant parts and animals coverings

Amino Acids

• Are the building blocks of proteins

• Contain a amino group, carboxyl group and one of twenty varying R groups

• Covalently bonded to a central carbon atom

Protein• Function as enzymes, in cell movements, as

storage, and transport agents (hormones, antibodies, and structural material)

• Amino acids are the building blocks of proteins (peptide bonds) – Amino acids coil into a 3D structure– Heat can denatured proteins causing a change

in shape and the ability to work properly

• Enzymes: special protein used to speed up a chemical reaction (biological catalyst)

Polypeptide Formation (2 to 3 amino acids)

Primary Structure• Primary structure is defined as ordered

sequences of amino acids each linked together by peptide bonds to form polypeptide bonds

• The sequence of amino acids to determined by DNA and is unique for each kind of protein

Continue: Secondary structure• Fibrous Proteins (beta pleated) : have

polypeptide chains organized as strands or sheets – Contribute to the shape, internal organization,

and movement of cells.

• Globular Proteins (alpha helix): have chains folded into compact rounded shapes– Example: Enzymes– Keratin

Secondary Structure

• Helical coil shape (e.g. Hemoglobin) or sheetlike array (as in silk) that results from hydrogen bonding of side groups on the amino acids chains.

Tertiary Structure

• Is the result of folding due to interactions among R groups along polypeptide chain

Quaternary Structure

• Two or more polypeptide chains

• Hemoglobin- four interacting chains that form a globular protein

• Keratin and collagen– complex fibrous proteins

Glycoproteins

• Consist of olgosaccharides covalently bonded to proteins

• Abundantly found in exterior of animal cells and blood

• Lipoproteins: have both lipid and protein components – Transport fats and cholesterol in the blood

Denaturation

• High Temperature or changes in pH can cause a loss of protein’s normal 3-D shape

• Pineapple– Fresh vs Canned and Jello

Why is protein so important?

• Alternation of a cell’s DNA can result in the wrong amino acid insertion in a polypeptide chain– Example: If valine is substituted for glutamate

in hemoglobin, the result is HbS (Sickle Cell Anemia)

• Person who inherit two mutated genes for the beta chain of hemoglobin can make HbS

• Causes a person blood to be shaped like a sickle not a round disk

Nucleotides and Nucleic Acid

• Nucleotides consists of a: 5 carbon sugar (ribose or deoxyribose), a nitrogen base, and phosphate group– Adenosine phosphate are chemical

messenger (cAMP) or energy carriers (ATP)– Nucleotide coenzyme transport hydrogen

atoms and electrons (example NAD+ and FAD)

– Nucleotides serve as a building block for nucleic acid

Nucleic Acid

• Are polymers of nucleotides– Four different kinds of nucleotides are strung

together to form large single or double-stranded molecules

– Each strand’s backbone consists of joined sugars and phosphates with nitrogen bases projecting toward interior

DNA vs RNA

• DNA– 2 strand– 5 carbon sugar:

Deoxyribose– Nitrogen bases:

Adenine, Thymine, Cytosine, Guanine

– Inheritance

• RNA– 1 strand– 5 carbon sugar:

Ribose– Nitrogen Bases:

adenine, uracil, cytosine, guanine

– Protein Synthesis