Lab 6, 8 Flashcards Preview

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Flashcards in Lab 6, 8 Deck (52)
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1
Q

 All living things are composed of

A

o Four basic classes of molecules: carbohydrates, proteins, lipids, and nucleic acid

2
Q

 Carbohydrates

A

– starch and sugar

3
Q

 Sugars

A

o Monosaccharide
o Simple molecules
o Made up of carbon hydrogen and oxygen
o glucose

4
Q

 Starches

A

o Long chains or polymers of simple sugars
o Polysaccharides
o amylose

5
Q

 How to detect the presence of different classes of molecules in solutions?

A

o By using specific agents

6
Q

 What to look for as an indication that a particular type of molecule is present?

A

o Change in color

7
Q

 What does it mean when the color changes?

A

o Test is positive for the presence of that particular molecule

8
Q

 How can we be sure that the physical changes we see are only due to the presence of the molecule?

A

o A control reaction is always performed for comparison

9
Q

 Distilled water in an experiment is an example of

A

o Control substance that provides a negative result

10
Q

 Testing for the presence of Starch in solution

A

o Add IKI solution 5 drops to 1% amylose

11
Q

 Adding IKI solution to starch will change the color from to?

A

o Brown to blue/black

o Positive

12
Q

 What solution to use when testing for sugar?

A

o 10 drops Benedict’s solution to 1% glucose

o Boil for 10 minutes

13
Q

 Adding Benedict’s solution to sugar/glucose will change the to color from to?

A

o Light blue to Orange means positive

14
Q

 Proteins

A

o Complex arrangements of amino acids
o Amino acids linked to each other in long chains
o gelatin

15
Q

 What solution to use when testing for protein?

A

o Biuret’s solution

o 1% gelatin

16
Q

 Adding Biuret’s solution to protein (gelatin) will change color from to?

A

o Light blue to pinkish purple

o Orange

17
Q

 Lipids

A

o Fats and oils

o Hydrophobic – does not mix with water

18
Q

 Fats

A

– solid at room temperature

19
Q

 Oil

A

– liquid at room temperature

20
Q

 Hydrophobic of lipids can be overcome by using what chemical and why?

A

o Bile salts

o Because they share both the properties of lipids and water (polarity)

21
Q

 How to test for lipids

A

o brown paper – one side of each drop distilled water and vegetable oil on other side and let dry for 5 minutes

22
Q

 what happens during the test for lipids? Why?

A

o Distilled water remains intact while the oil was absorbed by the paper
o water is cohesive with polar bond and wants to remain together while oil does not have same property

23
Q

 How to make lipid more soluble?

A

o 20 drops of water and 20 drops of oil with 20 drops of bile salts and mix
o because fat is hydrophobic and bile salt is hydrophilic the fat does not want to bind with salt

24
Q

 Procedures for making a 4% salt solution

A

o 8 gram of table salt NaCL and 192 ml of distilled water

25
Q

 Enzymes

A

o Facilitate and make possible most of the chemical reactions occurring in living organism

26
Q

 Which is the substrate, which is the enzyme: starch, amylase

A

o starch is substrate

o amylase enzyme

27
Q

 Digestion of starch happens in the human digestive system at 37 C, appropriate condition vs less than optimum condition

A

o appropriate condition: starch (polysaccharide is digested a disaacharide sugar (maltose) by the amylase enzyme (in saliva)
o les than: enzyme becomes denatured and lose its ability to function

28
Q

 denatured

A

o lose its conformational structure

29
Q

 Present of sugar is indicated byu appearance of a?

A

o Red, orange, or yellow

30
Q

 Describe the action of an enzyme in a chemical reaction

A

o It lowers the activation energy in a reaction

31
Q

What does it meanb when an enzyme has been denatured? What are consequences?

A


o Looses it conformational structure
o The substrate cannot bind with the enzyme

32
Q

 Each enzyme has a temperature and pH optimum. What does this mean?

A

o That the enzyme function at best at it’s optimum level during a certain temperature and pH

33
Q

 Can an enzyme be reused if it is destroyed during a chemical reaction?

A

o Yes, an enzyme remains unchanged to be used again and again

34
Q

 How does temperature affect enzyme function?

A

o Temperature speeds up the reaction, but the hotter it gets the possibility that the enzyme breaks down

35
Q

Reagent

A

– Indicator chemicals

36
Q

 How Does pH affect enzyme function

A

o The more basic it is the less effective the enzyme function is, the optimum level is at 7 pH, Acidic is slighty less than effective than pH7

37
Q

 How does concentration of the enzyme (amylase) affect starch digestion?

A

o It slightly make enzyme more effective

38
Q

 Can starches be broken down without enzymes?

A

o Yes by reaching the2 activation energy of the reaction without the help of Amylase
o it’s not done because the reaction takes a long time to activate

39
Q

 Passage of molecules into and out of cells is regulated by

A

o Plasma (cell) membrane

40
Q

 Selectively permeable membrane

A

o membrane allows only certain molecules to cross freely

41
Q

 Small molecules may simply diffuse across the plasma membrane, but large substances must?

A

o May need to be transported by carrier proteins that span the membrane

42
Q

 Diffusion

A

o Net movement of molecules from a region of higher concentration to a region of lower concentration

43
Q

 osmosis

A

o diffusion of water across deferentially permeable membrane from an area of higher water concentration to an area of lower water concentration

44
Q

 solution

A

o contains both a solute (particles) and a solvent (liquid) that dissolves the solute

45
Q

 tonicity

A

o relative concentration of solute and solvent outside of a cell compared to inside the cell

46
Q

 lysis

A

o disintegration of a cell by rupture of the cell wall or membrane

47
Q

 crenation

A

o eukaryotic cell – shrink after exposed to hypertonic solution

48
Q

 plasmolysis

A

o cell walls – cells lose water in hypertonic solution

o cell walls intact – inner membrane shrinks

49
Q

 emulsification

A

o breakdown of fat globules into smaller, uniformly distributed particles

50
Q

 bile

A

o mixture of substances that is produced by the liver and stored ibn the gallbladder
o emulsifies fats and aids in their digestion

51
Q

 monomer

A

o subunit that serves as a building block of a polymer

52
Q

 polymer

A

o a large molecule consisting of many identical or similar monomers linked together by covalent bonds