Organic molecules - Florida State College at Jacksonville



Worksheet 3: Organic molecules

This section will dealt with the main organic molecules in living things: carbohydrates, fats ( lipids ), proteins and nucleic acids.

A) Web site name: Florida State College Jacksonville

Web URL:

Read “Carbohydrates”

1) What does the body use carbohydrates for? ________________________

2) What two chemicals are given out when carbohydrates are burned? ____________________________________________________________

3) Why can cows survive on grass, but not humans? ____________________ _____________________________________________________________ _____________________________________________________________

Move down to the section “How sweet is your sugar?”

4) What is the sweetest chemical listed here? __________________________

5) Lactose is found in milk. Why does milk not taste very sweet? _____________________________________________________________

6) Plants and animals typically contain a lot of glucose. Most soft drinks such as Coke, Pepsi and Sprite contain fructose instead of glucose. Why is this? _____________________________________________________________

_____________________________________________________________

B) Web site name: John Jay College; New York

Web URL:

Read the section “Carbohydrates”

7) What three chemical elements are found in carbohydrates? _____________ _____________________________________________________________

8) Look at the chemical formula of glucose. How many Carbon (C) atoms does it have? ________________________________________________

9) What two molecules (or units) are joined to form sucrose? _____________________________________________________________

10) What is the difference between starch and glycogen? __________________ _____________________________________________________________

11) List four common sources of starch : _______________________________ _____________________________________________________________

C) Web site name: Health Check Systems

Web site address:

12) How many calories are there in 1 gram of carbohydrate?___________

1 gram of fat? ___________

13) Why are “Krispy Krunchies” not a very healthy choice of food? _________ _____________________________________________________________ _____________________________________________________________

Look at the “FDA Specifications for Healthy claims”

14) Does “Fat-Free” really mean “no fat”? _____________________________

Give a practical reason why it would be hard to label any food as “Fat-Free” if it had to have zero fat in it? ____________________________________ __________________________________________________________________________________________________________________________

15) What % of the Daily Values for Vitamin A, Vitamin C etc does food labeled “Healthy” have to have? ____________ %

16) Do you think any of these health claims on the chart are misleading? _____ If so, which ones? _____________________________________________ __________________________________________________________________________________________________________________________

D) Web site name: Mayo Clinic

Web URL:

Read “Nutrition and healthy eating”

17) What does dietary fat provide for the body? _________________________

18) What are four specific diseases that are a concern with some types of dietary fat and cholesterol? _____________________________________________________________ _____________________________________________________________

19) What are the main sources of harmful saturated fat? __________________________________________________________________________________________________________________________

20) List the main plant sources of healthier omega-3 fatty acids:

_____________________________________________________________

E) Web site name: New England Journal of Medicine

Web site address:

Read “Dietary Fat Intake and the Risk of Coronary Heart Disease in Women”

21) How many women in the study suffered from heart attacks ( myocardial infarction) ? ___________________________________________________

22) Was total fat intake related to the risk of coronary disease? _____________

23) How much does it reduce the risk of heart attack if women replace 5% of energy from saturated fats with energy from unsaturated fats? _______%

(Saturated and trans unsaturated fats are found in animal products (meat, milk) and margarine. Unsaturated fats are common in plants.)

F) Web site name: Science News

Web URL:

24) How many hours a day did the “limited eating” mice fast? ______________

25) After 100 days, how much less did the time-restricted feeding mice weigh compared to the mice who ate frequently? _______________________

26) What is “brown fat”? __________________________________________

____________________________________________________________

____________________________________________________________

27) Chronic inflammation has been implicated in which diseases? ______________________________________________________________________________________________________________________

G) Web site name: Florida State College at Jacksonville

Web URL:

28) What is the name for the two chemical groups (NH2 and COOH) bonded to the alpha carbon atom?

___________________________ and ____________________________

29) What is the “secondary structure” of a protein ? ____________________________________________________________

30) What is the molecular weight of insulin? _______________ daltons

31) What is meant by “Proteins can denature”? _________________________

_____________________________________________________________

H) Web site name: Florida State College at Jacksonville

Web URL:

32) When was the word “protein” first used? ___________________

33) What are the best sources of plant protein? __________________________

34) Many pharmacies and stores sell protein or amino acid pills as dietary supplements. What are two problems that can be caused by eating too much protein ? ______________________________________________________

35) If you are on a diet and eating very little food, why should you include some protein in your diet? ____________________________________________

I) Web site name: University of Connecticut

Web URL:

Read “Evidence that DNA is the genetic material”

36) Why did scientists in 1900 think that proteins were the genes, rather than DNA? _______________________________________________________ _____________________________________________________________

37) When did Alfred Hershey and Martha Chase finally show that DNA was responsible for bacterial virus infection? ____________________________

38) Who discovered in 1947 that the % of bases in DNA varies from organism to organism? _____________________________________________________________

39). What four bases (use letters) are found in DNA? _____________________

40). What is a helix? ________________________________________________

41). What does the enzyme helicase do? ________________________________

_____________________________________________________________

42). What does the enzyme ligase do? __________________________________

_____________________________________________________________

43). How many UV-induced errors in the DNA of every skin cell are caused by 4-hours at the beach? _________________________

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