8/13/2019 leture

1/4

1. BIOCHEMISTRY

2. CHEMISTRY OF LIFE Elements: simplest form of a substance - cannot be broken down any further without

changing what it is Atom: the actual basic unit - composed of protons, neutrons, and electrons

3. THE ATOM Just like cells are the basic unit of life, the ATOM is the basic unit of matter. They are very small. Ifplaced side by side one million would stretch a distance of 1cm. The atom is made up of 3 particles. Particle

Charge PROTON + NEUTRON NEUTRAL ELECTRON -

4. Electrons are not present within the atom, instead THEY REVOLVE AROUND THE NUCELUS OF THE ATOM &

FORM THE ELECTRON CLOUD Draw a helium atom. Indicate where the protons, neutrons and electrons are.

NEUTRONS PROTONS - ATOMIC # = 2 + + (PROTONS) ELECTRONS - ATOMIC MASS = 4 (PROTONS & NEUTRONS)

5. ISOTOPES atoms of the same element that HAVE A DIFFERENT NUMBER OF NEUTRONS Some isotopes are

radioactive. This means that their nuclei is unstable and will break down at a CONSTANT RATE over time. There

are several practical uses for radioactive isotopes: 1. CARBON DATING 2. TRACERS 3. KILL BACTERIA / CANCER

CELLS

6. COMPOUNDS a substance formed by the chemical combination of 2 or more elements in definite proportions

Ex: water, salt, glucose, carbon dioxide

7. The cell is a COMPLEX CHEMICAL FACTORY containing some of the same elements found in the nonliving

environment. (C) carbon, (H) hydrogen, (O) oxygen & (N) nitrogen are present in the greatest percentages

8. TWO TYPES OFCOMPOUNDS Organic - Contain C, H, and O in some ratio (usually referred to as chemicals of

life)Carbohydrates, Proteins, Lipids, Nucleic Acids Inorganic - usually "support" life - no specific ratio of C, H,

and OWater (H2O), Carbon Dioxide (CO2)

9. CHEMICAL BONDS Chemical bonds hold the atoms in a molecule together. There are 2 types of HIGH ENERGY

chemical bonds - IONIC and COVALENT

10. IONIC BONDS Occur when 1 or more electrons are TRANSFERRED from one atom to another. When an

atom loses an electron it is a POSITIVE charge. When an atom gains an electron it is a NEGATIVE charge These

newly charged atoms are now called IONSExample: NaCl (SALT)

11. COVALENT BONDS Occur when electrons are SHARED by atoms. These new structures that result from

covalent bonds are called MOLECULES ** In general, the more chemical bonds a molecule has the more energy it

contains SHARING IS CARING!

12. MIXTURES Water is not always pure. It is often found as part of a mixture. A mixture is a material composed

of TWO OR MORE ELEMENTS OR COMPOUNDS THAT ARE PHYSICALLY MIXEDEx: salt & pepper mixed, sugar and

sandcan be easily separated

13. SOLUTION Two parts: SOLUTE SUBSTANCE THAT IS BEING DISSOLVED (SUGAR / SALT) SOLVENT - thesubstance in which the solute dissolves Materials that do not dissolve are known as SUSPENSIONS.Blood is the

most common example of a suspension.Cells & other particles remain in suspension.

14. FORMULA The chemical symbols and numbers that compose a compound ("recipe") Structural Formula

Line drawings of the compound that shows the elements in proportion and how they are bonded Molecular

Formulathe ACTUAL formula for a compound C2H6O

8/13/2019 leture

2/4

15. ACIDS & BASES Acids: always (almost) begin with "H" because of the excess of H+ ions (hydrogen) Ex: lemon

juice (6), stomach acid (1.5), acid rain (4.5), normal rain (6) Facts about Acids Acids turn litmus paper RED and

usually taste SOUR. You eat acids daily (coffee, vinegar, soda, spicy foods, etc)

16. ACIDS & BASES Bases: always (almost) end with -OH because of the excess of hydroxide ions (Oxygen &

Hydrogen)EX: oven cleaner, bleach, ammonia, sea water, blood, pure water Facts about Bases Bases turn

litmus BLUE. Bases usually feel SLIPPERY to touch and taste BITTER.

17. Neutralization Reactions When an acid reacts with a base to produce a salt and water.

18. pH SCALE measures degree of substance alkalinity or acidity Ranges from 0 to 14 0 5 strong acid 6-7

neutral 8-14 strong base

19. The goal of the body is to maintainHOMEOSTASIS (neutrality)to do this when pH is concerned, we add

weak acids & bases to prevent sharp changes in pH. These are called BUFFERS

20. And now for theBiochemistry portion of things.

21. CARBOHYDRATES Living things use carbohydrates as a key source of ENERGY! Plants use carbohydrates for

structureCELLULOSE give structure to the Cell Wallinclude sugars &complex carbohydrates (starches)

contain the elements carbon, hydrogen, and oxygen (the H is in a 2:1 ratio to the O)

22. Monosaccharides (simple sugars) all have the formula C6 H12 O6 all have a single ring structure (glucose

is an example)

23. Disaccharides (double sugars) all have the formula C12 H22 O11 sucrose (table sugar) is an example

24. Polysaccharides(formed of three or more simple sugar units) Glycogen - animal starch stored in liver &

muscles Cellulose - indigestible in humans - forms cell walls Starches - used as energy storage

25. How are complexcarbohydrates formed and broken down?

26. Dehydration Synthesis Combining simple molecules to form a more complex one with the removal of water

monosaccharide + monosaccharide ---> disaccharide + water C6H12O6 + C6H12O6 -----------------> C12H22O11 +

H2O Polysaccharides are formed from repeated dehydration synthesis of waterThey are the stored extra sugars

known as starch

27. Hydrolysis Addition of WATER to a compound to SPLIT it into smaller subunits (also called chemical

digestion) disaccharide + H2O ---> monosaccharide + monosaccharide C12 H22 O11 + H2 O ------------> C6 H12 O6 +

C6 H12 O6

28. Lipids (Fats) Fats, oils, waxes, steroids Chiefly function in energy storage, protection, and insulation Contain

carbon, hydrogen, and oxygen but the H:O is not in a 2:1 ratio Tend to be large molecules -- an example of a

neutral lipid is below

29. Neutral lipids are formed from the union of one glycerol molecule and 3 fatty acids 3 fatty acids + glycerol ---

-> neutral fat (lipid) Fats -- found chiefly in animals Oils and waxes -- found chiefly in plants Oils are liquid at

room temperature, waxes are solids Lipids along with proteins are key components of cell membranes Steroids

are special lipids used to build many reproductive hormones and cholesterol

30. PROTEINS contain the elements carbon, hydrogen, oxygen, and nitrogen composed of MANY amino acid

subunits It is the arrangement of the amino acid that forms the primary structure of proteins. The basic amino

8/13/2019 leture

3/4

acid form has a carboxyl group on one end, a methyl group that only has one hydrogen in the middle, & an amino

group on the other end. Attached to the methyl group is a R group.

31. AN R GROUP IS ANY GROUPOF ATOMSTHIS CHANGESTHE PROPERTIES OF THEPROTEIN!

32. Major Protein Functions Growth and repair Energy Buffer -- helps keep body pH constant

33. FUNCTIONAL GROUPS There are certain groups of atoms that are frequently attached to the organic

molecules we will be studying, and these are called functional groups. These are things like hydroxyl groups which

form alcohols, carbonyl groups which form aldehydes or ketones, carboxyl groups which form carboxylic acids, and

amino groups which form amines.

dipeptide + water34. Dipeptide formed from two amino acid subunits Formed by the process of Dehydration

Synthesis amino acid + amino acid

35. Hydrolysis of a dipeptide Breaking down of a dipeptide into amino acids dipeptide + H2O ---> amino acid +

amino acid

36. Polypeptide (protein) composed of three or more amino acids linked by synthesis reactions Examples of

proteins include insulin, hemoglobin, and enzymes. ** There are an extremely large number of different

proteins. The variability include differences in the number, kinds and sequences of amino acids in the proteins

37. NUCLEIC ACIDS in all cells composed of NUCLEOTIDES store & transmit heredity/genetic information

Nucleotides consist of 3 parts: 1. 5-Carbon Sugar 2. Phosphate Group 3. Nitrogenous Base A, T, G, C

38. DNA (deoxyribonucleic acid) contains the genetic code of instructions that direct a cells behavior through the

synthesis of proteins found in the chromosomes of the nucleus (and a few other organelles)

39. RNA (ribonucleic acid) directs cellular protein synthesis found in ribosomes & nucleoli Nitrogenous Bases

(A, U, G, C)

40. CHEMICAL REACTIONS a process that changes one set of chemicals into another set of chemicals REACTANTSelements or compounds that enter into a chemical reaction PRODUCTS elements or compounds

that are produced in a chemical reaction Chemical reactions always involve the breaking of bonds in reactants

and the formation of new bonds in products.

41. In a reaction, energy is either TAKEN IN (ENDOTHERMIC) or GIVEN OFF (EXOTHERMIC) Can you think of an

everyday example of each type of reaction?

42. Enzymes and Enzyme Action catalyst: inorganic or organic substance which speeds up the rate of a chemical

reaction without entering the reaction itself enzymes: organic catalysts made of protein most enzyme names

end in -ase enzymes lower the energy needed to start a chemical reaction. (activation energy) begin to be

destroyed above 45oC. (above this temperature all proteins begin to be destroyed)

43. It is thought that, in order for an enzyme to affect the rate of a reaction, the following events must takeplace.1. The enzyme must form a temporary association with the substance or substances whose reaction rate it

affects. These substances are known as substrates.2. The association between enzyme and substrate is thought to

form a close physical association between the molecules and is called the enzyme-substrate complex.3. While the

enzyme-substrate complex is formed, enzyme action takes place.4. Upon completion of the reaction, the enzyme

and product(s) separate. The enzyme molecule is now available to form additional complexes.

44. How do enzymes work? substrate: molecules upon which an enzyme acts the enzyme is shaped so that it

can only lock up with a specific substrate molecule enzyme substrate -------------> product

8/13/2019 leture

4/4

45. "Lock and Key Theory" each enzyme is specific for one and ONLY one substrate (one lock - one key) this

theory has many weaknesses, but it explains some basic things about enzyme function

46. Factors Influencing Rate ofEnzyme Action 1. pH - the optimum (best) in most living things is close to 7 (neutral)

high or low pH levels usually slow enzyme activity A few enzymes (such as gastric protease) work best at a pH

of about 2.0

47. 2. Temperature - strongly influences enzyme activity optimum temperature for maximum enzyme function is

usually about 35-40 C. reactions proceed slowly below optimal temperatures above 45 C most enzymes are

denatured (change in their shape so the enzyme active site no longer fits with the substrate and the enzyme cant

function)

48. 3. Concentrations of Enzyme and Substrate ** When there is a fixed amount of enzyme and an excess of

substrate molecules -- the rate of reaction will increase to a point and then level off.