BIOL130L Study Guide - Red Blood Cell, Paper Chromatography, Litmus

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beigebee15

2 Dec 2013

School

University of Waterloo

Department

Biology

Course

BIOL130L

Professor

Heidi Engelhardt

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Document Summary

Time points: if time is a variable, you have to have a control for every time point in experiment. Positive control: should give positive result; negative control: should give negative result. Most abundant elements in living material: c, h, o, n, s, p. Biological macromolecules: carbohydrates (mono- and polysaccharides), lipids, proteins, nucleic acids. Normally pale yellow (turns black-blue for starch, reddish-brown for glycogen), change = positive. Benedicts test for reducing sugars carbohydrates can exist as straight chains or ring forms: in straight chain, aldehyde group ( ) makes it an aldose sugar aldehyde reacts in benedicts test to make glucose a reducing sugar. Positive: coloured precipitate yellow, green, red, brown. Benedicts contains blue cupric ions (cu++), when mixed with reducing sugars the aldehyde group reduces the cupric ions to cuprous ions (cu+), cuprous ions combine with oxygen, form precipitate of cuprous oxide (cu2o)

Related Questions

Benedicts Test for Reducing Sugars:

Tube Solution/food Color reaction to Benedicts solution Presence ofreducing sugar (green/reddish orange color)
1 1ml distilled water
2 good pinch glucose powder
3 good pinch table sugar (sucrose)
4 2 drops honey
5 finely chopped onion
6 finely chopped fruit
7 1ml milk
8
9
10

Which of the above solutions was included as your negative control?[1 pt]

Which of the above solutions was included as your positive control?[1 pt]

Which of the above foods/solutions tested positive for sugars? [4pts]

Explain why sucrose (table sugar) yielded the result above. [2pts]

What does this tell you about the way sugars are stored, forexample in onions? [2 pts]

Sugar is actually a common name for glucose. Glucose is stored asstarch in onions as it is a bulb present in plants.

Would you use the Benedicts test to investigate if a cake mix weresugar free? Explain your answer [2 pts]

The benedicts test cannot be used to determine if a cake mix issugar free or not. This is because benedicts test is used todetermine the presence of reducing sugars like maltose and lactose.Fructose also gives a positive test. We use sucrose in food so wecannot detect the presence or absence of sucrose in the cakemix

Iodine Test for Starch:

Depression Number Solution/food Color reaction to iodine solutionPresence of starch (bluish-black color)
1 Â½ ml distilled water
2 pinch glucose powder
3 pinch cornstarch
4 Â½ ml egg white
5 finely chopped onion
6 Finely chopped potato
7 1 drop honey
8
9
10

Which of the above solutions was included as your negative control?[1 pt]

Which of the above solutions was included as your positive control?[1 pt]

Which of the above foods/solutions tested positive for starch? [4pts]

Did any of the animal sources contain starch? Explain your answer.[2 pts]

Did any of the same foods test positive for both reducing sugars(Benedicts Test) and starch (Iodine Test)? Explain your answer. [4pts]

Proteins:
Tube Solution/food Color reaction to Biuret Reagent Presence ofprotein (violet color)
1 2ml distilled water
2 2ml milk
3 2ml egg white
4 2ml egg yolk
5 2ml honey
6
7
8
9
10

Which of the above foods/solutions tested positive for protein? [4pts]

Did any of the foods/solutions that tested positive for proteinalso test positive for reducing sugars (Benedicts Test) or starch(Iodine test)? Explain your answer. [2 pts]

How is the structure of proteins in plants and animals similar? [3pts]

How are proteins in plants and animals different? [3 pts]

Lipids:

Test Solution/food Grease spot indicating the presence oflipid
1 1ml distilled water
2 Oil-vinegar salad dressing
3 walnut
4 Egg white (wipe away excess)
5 Egg yolk (wipe away excess)
6
7
8
9
10

Which of the foods tested were positive for the presence of lipid?[4 pts]

Part 2 â Tracking Macromolecules in Your Diet

Include a copy of your ânutrient intakeâ and record the followingnutrient intakes in the space below. NOTE: Nutrient Intake is thename of the report generated at www.MyPyramid.gov [10 pts]

Kilocalories Percent Total Recommended
Energy Intake Intake

Carbohydrate ___________ ______________ 45-65%

Protein ________________ ______________ 10-35%

Total Fat _______________ _______________ 20-35%

Show your calculations in the space below

How did your consumption of macronutrients compare to therecommended intake?

orangehippopotamus244

Life Chemistry LabReport

Elements of Living Organisms
Name the five most abundant elements found in the humanbody.

Cells organize into tissues which work together to form

What is the difference between an atom and an element?

Molecules

Is glucose an atom or molecule? What are the atoms inglucose?

How many bonds can oxygen form?

Is C₆H₁₂O₆ a molecular orstructural formula? What is the name of this molecule?

Based on lab, Section II, draw and label a ball and stickrepresentation of a carbon dioxide, water and ethyl alcoholmolecule. Use circles to designate atoms and lines for bonds, thenindicate the chemical symbol for each atom. Sign, date and preparean image of your drawing and include it with this lab report.

Molecular Make Up of Living Organisms

Name the four groups of organic molecules.

_______ are the most abundant organic molecules in livingorganisms.

Name a polysaccharide, monosaccharide, protein and alipid.

Go to the lab, Section 3, Exercises 2, 3, 4 and 5 to completethe following table:

Type of Organic Molecule	Reagent	Sample Tested	Positive Color	Negative Color
Carbohydrate (starch)	Iodine
Sugar	Benedictâs solution
Lipid (fat)	Sudan IV
Protein	Biuret

Go to the lab, Section 3, Exercise 6 to locate starch in potatocells. Describe the microscopic appearance of starch in terms ofcolor and location within the cells.

Measurement of pH

What substance has an equal number of hydrogen ions(H⁺) and hydroxide ions (OH^-)?

What is the pH of the above substance?

How does the addition of hydroxide ions (OH^-) affectthe pH of your stomach?

Go to lab, Section 4, Exercise 7 to test the pH of commonsolutions. Which solution tested had a pH closest to neutral? Whichsolution was most acidic?

Summary Questions

What is the smallest subunit of carbohydrates?

Which reagent could be used to test for diabetes?

A member of your family has a high blood cholesterol count. Yousee âfat freeâ crackers in the grocery store and decide to test theproduct for the presence of lipids. How would this testproceed?

A family member has been cautioned about eating foods high insugar. Explain how a test could be run for the presence ofsugar.

Explain how to test for the presence of protein in milk.

A friend complains of stomach acidity. Which substance testedmight safely help relieve your friendâs symptoms?

Explain how solutions are classified as acids or bases. Then,give an example of a weak acid.

brownclam274

26.The best microscopy technique for observing different subcellular structures on the surface of bacteria is

(A) SEM (B) TEM

(E) fluorescence microscopy

27.Which type of microscopy exploits differences in the refractive index of the specimen, where light is retarded by one-quarter of a wavelength when it passes through a bacterial cell?

(A) SEM (B) TEM

(E) fluorescence microscopy

28.Which type of microscopy should be used to examine bacterial cells that have been Gram stained?

(A) TEM (B) fluorescence microscopy

(E) bright-field microscopy

29.Which of the following is most abundant in a prokaryotic cell (in dry weight)?

(A) RNA (B) DNA

(E) Lipid

30.Which of the following techniques uses the Svedberg unit (S)?

(A) electron microscopy (B) ultracentrifugation

(E) sonication

31.Which of the following is NOT a function performed by the cell membrane or its components?

(A) production of proteins (B) detection of environmental signals

(E) B and D

32.Which of the following statement is true?

(A) Lipopolysaccharides (LPS) are found in the cell wall of Gram-negative bacteria.

(B) Lipopolysaccharides (LPS) are found in the cell wall of Gram-positive bacteria.

(D) Teichoic acids are found in the cell wall of Gram-positive bacteria.

(E) Cholesterol is found in the cell wall of Gram-negative bacteria.

33.Which of the following is found in Archaeabut not in Bacteria?

(A) Hopanoids (B) Terpenoids

(E) Peptidoglycan

34.The glycan chain of archaeal cell wall is made of __________ and __________, while the glycan chain of bacterial cell wall is made of __________ and __________.

(A) peptidoglycan and murein, pseudopeptidoglycan and murein

(B) N-acetylglucosamine and N-acetyltalosaminuronic acid,

N-acetylmuramic acid and N-acetyltalosaminuronic acid

N-acetylglucosamine and N-acetylmuramic acid

(D) N-acetylglucosamine and N-acetylmuramic acid,

N-acetylglucosamine and N-acetyltalosaminuronic acid

(E) N-acetylmuramic acid and N-acetyltalosaminuronic acid,

N-acetylglucosamine and N-acetyltalosaminuronic acid

35.The sacculus of bacteria is composed primarily of

(A) phospholipids (B) peptidoglycans

(E) nucleic acids

36.Lysozyme attacks the following linkage in the bacterial cell wall:

(A) Î²(1,4)-glycosidic bonds

(B) Î²(1,3)-glycosidic bonds

(D) Peptide cross-links between glycan chains

(E) Peptide bonds between L-alanine and D-glutamic acid

BIOL130L Study Guide - Red Blood Cell, Paper Chromatography, Litmus

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