Bio 160

Bio 160

Unit 1-2Week One- Lecture Two

Writing Chemical Formulas

• 2 methods– Molecular formula- shows the atoms and their

numbers, but not how they are bonded• H2O, C6H12O6

– Structural formula- shows the atoms and their numbers but also gives a “picture” or structural map of how the atoms are bonded together

• The sticks represent bonds

Organic Compounds

• Organic compounds are synthesized by cells and contain carbon atoms– Carbon has 4e- in outer shell, so has a high

affinity for bonding covalently• Will bond in single or double bonds

– Hydrocarbons- compounds formed with only carbon and hydrogen atoms

• Can create long chains of carbon or a carbon skeleton

Organic Compounds

• Carbon skeleton can contain same number of atoms but be shaped differently, creating an isomer

– Each isomer, while made up of the same number of atoms, has its own unique properties because of its shape

Organic Compounds

– Functional groups- usually only certain areas of an organic molecule participate in bonding. That area is called a functional group

• 4 major functional groups important for sustaining life

– Hydroxyl- OH

– Amino- NH2

– Carbonyl- CO– Carboxyl- COOH

Organic Compounds

• All 4 groups are highly polar, making them hydrophilic and soluble in water

– Water is essential for proper metabolic functioning and this is why

• Many biological molecules may contain 2 or more functional groups

Organic Compounds

– Macromolecules- huge organic chains of molecules

• Polymers- large molecule consisting of many similar or identical units

• Monomers- stick together to create polymers– Polymers stick together to create macromolecules– 40-50 common monomers, plus a few rare ones create

the multitude of different biological molecules

Organic Compounds

– Reaction types• Dehydration synthesis: the creation of polymers by

linking an H of one monomer to an OH of another, liberating water (H2O) in the process

• Hydrolysis: the breaking down of macromolecules by adding water, breaking the bonds between monomers, giving an OH on one and giving an H to another

4 classes of macromolecules necessary to life

• Carbohydrates– Ranges from small sugar molecules to up to

long macromolecules– Monosaccharides- simple sugars usually have

an –ose ending• Some ratio of C : H2 : O• Glucose C6H12O6

• Fructose isomer of glucose (has the same number of atoms as glucose but arranged differently)

• Glucose is the key sugar for cellular E and the necessary end product of the small intestine digestive system

4 Classes of Macro…cont

– Disaccharides-double sugar• Comes from the dehydration synthesis of 2

monosaccharide• Most common is sucrose-table sugar

– Fructose + glucose = sucrose

– Polysaccharides- “many” sugars• Starch- storage sugar- broken down as needed to

be released as glucose – Can be hydrolyzed quickly by digestive system


• Cellulose- forms cell walls of plants– Most abundant compound on earth– Closely resembles starch and glycogen but shaped

differently» Fibrils lay side by side and are joined together by

hydrogen bonds, forming a tough, fibrous wall» Supports plants and trees

– Cannot be hydrolyzed by animals unless they have cellulose hydrolyzing microorganisms in their gut

» Does provide “roughage” in diet, but does not give nutrition


• Lipids- Fats– Carbon- hydrogen chains

• Non-polar, therefore hydrophobic and will not dissolve in water

– Fats are composed of glycerol molecule and a fatty acid molecule

• 1 glycerol + 3 fatty acids = 1 triglyceride• Body naturally manufactures triglycerides but when

you include too much fat in the diet, body makes more than needed and gets stored in fat cells or free floats in blood

– Genetic conditions may cause body to overproduce triglycerides, increasing concentration in the blood


– Unsaturated vs. saturated fats• Fat molecules are chains of carbons• How the H’s arrange around the C’s determines

whether fat is saturated or unsaturated– Unsaturated have double bonds so not all C’s have H’s

surrounding them. Therefore the molecule cannot tightly pack and can be “broken down” much easier in digestive tract

» Remain liquid at room temperature» Plant origins


– Saturated fats contain no double bonds, so every C has H’s around it, saturating it. Molecule becomes tightly packed; hard to break down in system and remains solid at room temperature, mostly animal in origin


– Phospholipids contain an atom of phosphorous and have only 2 fatty acids

• Major component of cell membranes• Hydrophobic, protects the cell

– Wax- 1 fatty acid linked to an alcohol• Protect surfaces from drying out

– Steroids- form carbon rings (non anabolic)• Cholesterol- steroid found in cell membranes and

used in the manufacture of other types of steroids


• Proteins- made of chains of amino acids– Several different classes of proteins

• Structural- hair, tendon/ ligament fibers• Contractile- muscles• Storage- egg whites (food supply for embryos)• Defensive- antibodies

• Transport- hemoglobin- carries O2

• Signal-some hormones carry body messages• Enzyme- control rates of chemical reactions

without it being used or changed in any way


– 20 amino acids make up all the different types of proteins

• All amino acids contain an amino group, carboxyl group and an R group

• 1

– It is the R group that makes each amino acid different


– Amino acids linked by peptide bonds, where the carboxyl group of one links with the amino group N of another in dehydration synthesis, creating the polypeptide bond.

– The shape of the protein determines its function

• Primary shape- the sequence of amino acids• When shape is altered, the functioning ability of the

protein is altered as well– Denaturing- altering of protein

» Heat, radiation, freezing, pH, salt


• Nucleic Acids-– Deoxyribonucleic Acid

• Contains the genetic material or code of the organism

– Determines what proteins need to be made and when.

• Made of Nucleotides– A sugar (deoxyribose), a phosphate, and nitrogen base

(A, T, G, C)

• Shaped in a double helix- (double stranded spiral)- one side is a compliment of the other

• Cannot leave the nucleus of the cell– A-T G-C

Prokaryote cells vs. Eukaryotes

• Prokaryote cells are ancient cells and have no organized nucleus. (Bacteria, Archea)– Its DNA is coiled into a nucleotide region but

is not differentiated with membrane– Contain ribosomes, plasma membrane,

cytoplasm– Some have a bacterial cell wall outside the

plasma membrane and others also have a capsule for protection and adhesion.

– May also have pilli and prokaryotic flagella

Pro. Vs Euk. cont…

• Eukaryotic cells make up all other forms of cells

• Evolved from prokaryotic cell relationships– Have highly organized and specialized

organelles

Eukaryotic Cell Organelles (parts) and functions in brief

• Not every cell has every organelle– Plant and animal cells do differ in some ways

• Organelles– General Manufacturing function

• Nucleus• Ribosomes• Rough endoplasmic reticulum (has ribosomes

attached)• Smooth endoplasmic reticulum• Golgi bodies (complex, apparatus)

Eukaryotic Cell Organelles cont…

– General breakdown function• Lysosomes• Peroxisomes (break down materials using

hydrogen peroxide H2O2)

• Vacuoles

– Energy Processing functions• Mitochondria- found in both plant and animals• Cholorplasts- found in plants and some protists

Eukaryotic Cell Organelles cont…

– Support, movement, communication functions• Cytoskeleton

– Cilia, flagella, centrioles, microfilaments

• Cell wall- in plants• Extracellular matrix- in animals

– Sticky glycoproteins

• Cell junctions– Tight, anchoring, communication– Plants- plasmodesmata (channels between plant cells)

Bio 160

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