Practical Exam 1

Question 1

an “educated guess” as to answer a scientific question

Answer 1

hypothesis

Question 2

can be manipulated or changed by the researcher

Answer 2

independent variable

Question 3

the observed (measured or counted) outcome of the test; depends on what is manipulated

Answer 3

dependent variable

Question 4

all other variables that must remain constant during the test

Answer 4

control

Question 5

name the scientific measurements (3)

Answer 5

meter, liter, kilogram

Question 6

what does C.M.M.N stand for

Answer 6

centi, milli, micro, nano

Question 7

list the four types of organic compounds

Answer 7

carbohydrates, lipids, proteins, and nucleic acids

Question 8

heat the test tubes over an open flame and note the black residue in the test tube

Answer 8

how to test for organic components

Question 9

contains copper ions in alkaline solution. when reagent is heated the copper ions turn a metallic copper

Answer 9

benedict’s test for reducing sugars

Question 10

molecules get stuck in the spirals of another molecule and cause a blue-black color to appear.

Answer 10

iodine test for starch

Question 11

a mixture of two liquids, each insoluble in the other

Answer 11

emulsion

Question 12

molecule that is water-soluble on one end and lipid-soluble on the other.

Answer 12

emulsifier

Question 13

a transparent to translucent spot

Answer 13

positive for a lipd

Question 14

a solution of sodium hydroxide and copper sulfate turn a violet color because of a reaction with the peptide bods that link the individual amino acids

Answer 14

biuret reagent for proteins

Question 15

the smallest unit of life

Answer 15

cell

Question 16

have specialized structures called organelles

Answer 16

eukaryotic cells

Question 17

do not have any internal membranes and no membrane-bound organelles

Answer 17

prokaryotic cells

Question 18

particles tend to move from high concentration to low until a uniform distribution

Answer 18

diffusion

Question 19

diffusion of water molecules through a semi-permeable membrane

Answer 19

osmosis

Question 20

certain substances diffuse freely through the cell membrane without any expenditure of energy

Answer 20

passive transport

Question 21

allows some particles to pass through while restrict the movement of others

Answer 21

selective permeability

Question 22

random motion of particles suspended in a fluid resulting in a transfer of kinetic energy (heat)

Answer 22

brownian motion

Question 23

proteins that act as catalysts

Answer 23

enzymes

Question 24

molecule that the enzyme will alter

Answer 24

substrate

Question 25

four factors that affect enzyme activity

Answer 25

temperature, pH, substrate concentration, enzyme concentration

Question 26

substance that consists of acid and base and is resistant to pH change

Answer 26

buffer