Bio Lab Ch 1 & 4

tentatively explains somthing observed (proposes an answer to a question - suggest a possible explanation)

*MUST BE TESTABLE AND FALSIFIABLE*

Watson & Crick

• 1) Ask a question (must be testable - not subjective eg pretty, smart)
• 2) Develop a hypothesis
• 3) Design an experiment to test the hypothesis (experimental design)
• 4) Make a prediction
• 5) Conduct experiment

• 1)Determine All Variables
• a. Dependent Variable
• b. Independent Variable
• c. Controlled Variables
• 2)Develop a procedure
• a. Level of Treatment
• b. Replication
• c. Control

measured, counted, or observed in response to the experimental conditions

experimental condition which is manipulated to test the hypothesis

*most important variable by which to text the hypothesis*

ENVIRONMENTAL FACTORS

The variables that must be kept consistant during the experiment

sequence of steps to be performed for the experiment

value set for the independent variable (specifically amount used for the test)

in some experiments there is no level of treatment

procedure should be repeated several times, providing consistant results

Hold the same (placebo)

the indenpendent variable is held at established level or omitted. Allows scientist to decide if the effect is really due to the indepentent variable.

If/ then statement

If the hypothesis is true/ then the results of the experiment will be....

qualitative - subjective - quality such at pretty or smart cannot be measured by science

quantatative - objective - data - measurable

growth at the same rate - two body parts grow at the same rate. Proportions between body parts remain constant as the organism grows.

growth at different rates - parts of an organism grow at different rates

x axis - horizontal

y axis - vertical

• 1) Title - clearly tells what graph is about - goes BELOW the graph - Cap first work and period at the end.
• 2) Key - what the different lines or dots represent
• 3) X axis labeled - (indedendent variable) what measured and measurement used (^oC, cm, mm)
• 4) Y axis labeled - (dependent variable) what measured and measurement used
• 5) line of best fit (optional) dont connect the dots

independent - x axis

Height/ Body Part = ratio

Independent was the body part (head circumference)

Dependent was the ratio H/BP

figures

1. Help you analyze and interpret your results

2. Enhance the clarity with which you present the work to your reader

• 1. All values of the same kind should read down the column
• 2. Column headings should include unit of measure (if appropricate)
• 3. Title - should be clear and concise - Goes at the TOP of the table - cap first word and important words...no period
• 4. Include replication if appropriate

Show changes in the quantity of the chosen variable and emphisize the rise and fall of values over their range. ( use to present continuous data)

• 1. plot data as seperate points
• 2. use line of best fit (normally) - only connect points when emphesizing changes in the independent (x) variable
• 3. If more than one set of data - use different colors and include a key

Used for data that represents separate or discontinuous groups or non-numerical categories

Histograms are bar graphs in which the values on the x axis are numbered but grouped together.

Science assumes that boilogical systems are understandable and can be explained by fundamental rules or laws

Long chains of amino acids (monomer)

20

Peptide bond which is created by dehydration synthesis

bilogical catalyst - a compound that speeds up a chemical reaction without being used up or altered in the reaction.

speed up the reaction by lowering the activation energy necessary for the reaction to occur

Without enzymes most reactions could not happen quickly enough

Each enzyme must have it own specific shape

Each enzyme can only hold a particular substrate

Enzymes hold reactants in a particular configuration so that a reaction can occur (lock and Key model)

Enzymes are proteins that are highly specific in function

the material that the catalyst (enzyme) acts upon

the substrate is modified during the reaction to form a new product

part of the enzyme that binds the substrate (forming the enzyme-substrate complex)

bond of enzyme and substrate

after the enzyme had done it work the complex disassociates into enzyme and product (or products)

environmental factors such as pH & temperature - can change the three-dimensional shape of the enzyme and alter its rate of activity

enzymes in the human body are designed to work at pH 7 and about 37^oC

Chemicals that must bind to the enzyme for it to be active (binds and changes it shape)

example - perms - solution dosent work until activator is applied

nonprotein substances that bind to the active site of an enzyme and are essential for the enzyme to work

organic (biological materials) that are needed for the enzyme to function properly

many vitamins are coenzymes - if the body is deficient in a certain vitamin then enzymes that need that vitamin will not work right

chemicals that shut off enzyme activity

compeditive and noncompeditive inhibitors

compete with the normal substrate for the active site

adding more substrate can overwelm the compeditive inhibiter and cause it not to work

Antifreeze and alcohol

binds to some other part of the enzyme - changes the shape (configuration) of the enzyme

AChE inhibitors - (pestcides causes enzyme processos of insect body to not be able to work)

1. Determine rate of disappearance of the substrate

2. determine rate of appearance of the product

• 1. a substrate or substrates bind to the active siteof the enzyme
• 2. forming the enzyme-substrate complex
• 3. which then disassociates into enzyme and product or products

Enzymes can bind substrates together or break them apart

-ase

-ose

enzyme that in the presence of oxygen, causes the removal of electrons and hydrogens from catechol (compound in plant cells). Catechol is converted to benzoquinone (pigment product) and water.

Catechol + 1/2 O_{2 →Catechol oxidase}→ Benzoquinone + H₂O

this reactions is what causes fruits and vegetables to turn brown when exposed to air

PTU - phenylthiourea

to be active Catechol oxidase required copper as a cofactor. PTU combines with the copper in the catechol oxidase and inhibits its enzymatic activity

noncompeditive inhibitor

• enzyme in the saliva of many animals, including humans
• breaks up starch (polysaccharide) into maltose (disaccaride)

• Starch turns purple
• Malose does not react to I₂KI

allows quantatative measure of reaction rate by watching how quickly starch disappears when treated with the enzyme amylase

sample

take an aliquot (sample) of enzyme and dilute it with an equal amount of water (1:1) Take an aliquot of the dilutution and add to an equal amount of water (1:3) and so on (1:7), (1:15), (1:31)

The deaction rate (the dependent variable) was measured as time of starch disappearance - the highest values indicate the slowest reaction time

• Independent - Enzyme concentration
• Dependent - Reaction rate (time of starch disappearance)
• As the enzyme amylase concentration is resuced, reaction times get slower and slower until there is no reaction because there is not enough amylase

• Independnet - pH
• dependent - Recation rate (in seconds)
• Each enzyme has a pH range that it works best at (pH can affect the three-dimensional shape of the the enzyme). Amylase works best at pH near 7 and slower at lower and higher pH (bell shaped graph)

chemical reactions accelerate as temp rises - increased temp speeds up motion of molecule

10^o rise in temp will result in two to three fold increase in reaction

• Independent - Temperature
• Dependent - Reaction Rate
• Enzyme have an optimal temp that they work best at. Amylase works best near 37^oC. It does not work at 4^o or 80^o (bell shaped graph)
• High Temperature can cause the integrity of the protein to be permanently denatured.