Lab Practical Exam 1 Review

Question 1

Benedict reagent

Answer 1

is used to identify simple sugars.

Question 2

The reaction requires heat to take place.

Answer 2

Benedict reagent

Question 3

Glucose

Answer 3

six-carbon sugar molecule in starch and glycogen. A common monosaccharide.

Question 4

Disaccharide

Answer 4

A carbohydrate made up of two sugar molecules linked together.

Question 5

Maltose

Answer 5

A disaccharide consisting of two glucose molecules bound together.

Question 6

Simple sugar

Answer 6

Monosaccharides and disaccharides.

Question 7

Oligosaccharide

Answer 7

A carbohydrate made up of more than two sugar molecules linked together.

Question 8

Polysaccharide

Answer 8

A carbohydrate made up of hundreds to thousands of sugar molecules linked together.

Question 9

Starch

Answer 9

A plant-based polysaccharide.

Question 10

Glycogen

Answer 10

An animal-based polysaccharide.

Question 11

• Benedict test for sugar

Answer 11

A light blue solution that tests for many types of simple sugars, including maltose and glucose.

Light blue (original color) = no simple sugars. The color then progresses through green, yellow, orange, red, and brown as the amount of simple sugars increases.

Question 12

Iodine

Answer 12

A solution that turns from brown to purple in the presence of starch.

Question 13

Positive control

Answer 13

Any procedure that is known to produce the desired result. A positive test result means what you are looking for is present.

Question 14

Negative control

Answer 14

Any procedure that is known to NOT produce the desired result. A negative test result means what you are looking for is NOT present.

Question 15

How to interpret the starch test

Answer 15

A positive test result for starch occurs when iodine turns color. Medium blue is a small amount of starch, dark blue indicates a medium amount of starch, and blue-black indicates a large amount of starch. A negative test result for starch occurs when iodine stays yellow.

Question 16

Lipid

Answer 16

A macromolecule made up of dozens to hundreds of molecules of mostly carbon and hydrogen.

Question 17

Cholesterol

Answer 17

A lipid with a structure containing over 20 carbon atoms configured into four rings.

Question 18

+ Phospholipid

Answer 18

A lipid made up of a three-carbon glycerol molecule with a phosphate group and two fatty acids attached.

Question 19

Triglyceride

Answer 19

A lipid made up of a three-carbon glycerol molecule with three fatty acid chains attached to it.

Question 20

Fatty acids

Answer 20

Long chains of carbon with hydrogen attached, making them nonpolar molecules.

Question 21

Saturated fatty acid

Answer 21

A chain of carbon atoms using only single carbon-to-carbon bonds with hydrogen atoms attached to the carbon atoms.

Question 22

Unsaturated fatty acid

Answer 22

A chain of carbon atoms that contain one (monounsaturated) or more (polyunsaturated) double bonds between carbons with hydrogen atoms attached to the carbon atoms.

Question 23

How to interpret the paper test:

Answer 23

A positive result for a lipid will result in an evenly distributed oily stain remaining on paper after 15 minutes. Water will completely evaporate, and nonlipid substances mixed with water will leave a circular stain.

Question 24

A fatty acid with three double bonds.

Answer 24

This is a polyunsaturated fatty acid.

Question 25

Biuret reagent

Answer 25

A light blue reagent that tests for protein.

Question 26

How to interpret the Biuret test:

Answer 26

A positive result for the Biuret test occurs anytime the reagent changes from its original blue color to a pink or purple color. Any tube that is blue, no matter which shade of blue, does not contain protein. turns from light blue to pink if a low concentration of protein is present. Dark purple indicates a high protein concentration.

Question 27

polymers consisting of long chains of amino acid monomers.

Answer 27

Proteins

Question 28

Two amino acids form a .

Answer 28

dipeptide

Question 29

Multiple amino acids folded to form a

Answer 29

functional structure make up a protein.

Question 30

Magnification

Answer 30

the apparent increase in image size.

Question 31

Resolution

Answer 31

the ability to distinguish fine detail.

Question 32

Contrast

Answer 32

the ability to distinguish objects, such as cells, from the background.

Question 33

advantages of a wet mount may include

Answer 33

Fast preparation. Requires no special equipment other than a transfer pipette, slide, and cover slip. Organisms may be viewed in their living state. Movement of motile microorganisms can be observed.

Question 34

Diffusion

Answer 34

the net movement of a solute from an area of higher concentration to an area of lower concentration.

Question 35

Diffusion is the result of

Answer 35

the random movement of molecules.

Question 36

The rate of diffusion may be influenced by

Answer 36

density of media, concentration gradient, temperature, molecular size, and membrane permeability.

Question 37

Media

Answer 37

Substance through which diffusion occurs, such as water and air.

Question 38

Hypertonic

Answer 38

A solution with a higher concentration of nonpermeable solutes in comparison to another solution.

Question 39

Hypotonic

Answer 39

A solution with a lower concentration of nonpermeable solutes in comparison to another solution.

Question 40

Osmosis

Answer 40

Osmosis is the movement of water across a selectively permeable membrane from a hypotonic solution into a hypertonic solution.

Question 41

Osmotic pressure

Answer 41

The pressure applied to a selectively permeable membrane to prevent osmosis.

Question 42

What effect does corn syrup concentration have on the movement of water in this simulation?

Answer 42

More water is drawn up into the thistle tube with higher concentrations of corn syrup.

Question 43

When experimenting with a selectively permeable membrane, Diffusion occurred based on

Answer 43

molecular size. Iodine and glucose are much smaller molecules than starch; therefore, they were able to diffuse.

Question 44

Tonicity

Answer 44

The ability of a solution to change the volume of a cell through osmosis.