Bio112 Midterm

lab lessons 1-7

scientific claims

can be tested using the scientific method

secondary literature

magazines, textbooks, the internet

primary literature

peer reviewed

Dr. Andrew Wakefield

preformed a poorly back “study” to test the correlation of the MMR vaccine to autism

review articles

a unique type of secondary literature that summarizes the works of many primary literature articles and are a good source for reliable scientific information

how can you find primary literature?

medical journals, google scholar

The scientific method

1. observe

2. ask questions

3. hypothesize

4. test the hypothesis

5. analyze the resulting data

6. form a conclusion

independent variable

what is being tested?

treatment

a condition that has 1+ variable(S) that differ

dependent variable

the thing that changes due to the independent variable

H₀ null hypothesis

a statement that presumes no change

H_a alternative hypothesis

a statement that describes change

“n”

typically describes sample size

T-test

determines the probability that two averages/means come from the same population or from two distinct populations

P-value

the functional value. If it is equal to or less than “a” then the null hypothesis is rejcted

lesson three

testing mealworms reactions to different nutritional substances. The control was sand/water

L3 null hypothesis

the mealworms will be attracted to both the sugar and salt, but are unresponsive to the sand

L3 alternative hypothesis

the mealworms will be more attracted to the sugar rather than the salt

why is conducting replicates important?

it ensures that the data is consistent

why are control groups important?

they provide a base line set of data to compare the rest of the results to.

the metric system of measurement

length, mass (weight), and volume

base unit for length

meter (m)

base unit for mass (weight)

gram (g)

base unit for volume

liter (L)

nano-

10^-9 , a billionth of the base unit

micro-

10^-6 , a millionth of the base unit

milli-

10^-3 a thousandth of the base unit

centi- 

10^-2 , a hundreth of the base unit 

deci-

10^-1 , a tenth of the base unit

deka- 

10¹ , ten of the base unit

hecto-

10² , a hundred of the base unit

kilo-

10³ , a thousand of the base unit

mega-

10⁶ , a million of the base unit

giga-

10⁹ , a billion of the base unit

to move from a larger unit to a smaller unit

multiply by 10, decimal moves to the right

to move from a smaller unit to a larger unit

divide by 10, decimal moves to the left

solvent

the bulk of the solution, normally water.

solute

the chemical dissolved in the solvent

formula for molarity

M= the number of moles / liters of solution

to make a solution with a concentration other than 1M

multiply the atomic mass of the compound by the desired molarity

dilution

adding a certain volume of stock solution to a certain volume of solvent

the formula used to calculate dilutions of a stock solution

C₁ x V₁ = C₂ x V₂

diffusion

the result of the random movement of individual molecules (or ions) from a more concentrated region into a less concentrated region

concentration gradient

when molecules move down (greater concentration to lesser concentration)  in absence of other forces

characteristics of diffusion

1. each molecule/ion moves independently of others

2. molecule movements are random

3. no energy is required/used in the process

equilibrium

when the diffusing molecules are equally distributed

when does diffusion occur more rapidly?

at high temperatures

osmosis

the net diffusion of water across a semi-permeable membrane

in osmosis, water moves

from the side of the membrane with a higher concentration of water and less solutes to the side of the membrane with lower water concentration and more solutes

tonicity

the concentration of solutes and solvent on either side of a membrane

isotonic

solutions that have equal concentrations on either side of a membrane

hypotonic

a solution that has less solute and more water

hypertonic

a solution that has more solute and less water

hypotonic cell

swollen, water moves into this cell to balance the solute concentration

isotonic cell

no change, no net movement occurs

hypertonic cell

shrivels, water moves out of the cell into the environment with more solutes and less water

Lesson 6

diffusion and osmosis, performed a lab with dialysis bags and a sucrose solution

Lesson 7

enzymes, performed a lab with potatoes, water, and hydrogen peroxide. measured the height of the oxidation bubbles

enzymes

protein molecules that function by lowering activation energy needed in a chemical reaction

E_a activation energy

the energy required for a chemical reaction to occur

the shape of an enzyme

3D, is unique, produces an active site that will only bind with one type of substrate

catalase

an enzyme that is present in the peroxisome organelle and functions to speed up the breakdown of hydrogen peroxide within cells

a buildup of hydrogen peroxide causes

denaturing of cellular molecules, including DNA