Werkgroep 1. Introduction
Can we get fat from eating carbohydrates?
A carbohydrate is a biological molecule consisting
of carbon (C), hydrogen (H) and oxygen (O) atoms, The term is most
common in biochemistry, where it is a synonym of 'saccharide', a group
that includes sugars, starch, and cellulose. In food science the term
carbohydrate often means any food that is particularly rich in the complex
carbohydrate starch and sugar such as bread, pasta, candy, jam and
desserts.
1. Nothing lasts forever. How long does a covalent bond in a DNA
molecule last?
If not forever, then a very, very long time
2. How do Italians traditionally make balsamic vinegar for a salad
dressing?
Balsamic viegar is produced by slow fermetation of a
concentration of the juice of cooked white gapes. In this process
acetate is produced.
3. What are the crunchy white little crystals in mature cheese?
Calcium lactate; micro-organisms produce lactate via glycolysis
and secrete it into the cheese.
4. What tastes sweeter, honey or table sugar?
Honey tastes sweeter because it contains free fructose (glucose
+ fructose)
5. How does the cell retrieve energy from the reaction: C6H12O6 + 6
O2 ! 6 CO2 + 6 H2O?
ATP is produced via a proces called intermediary metabolism.
During this proces glucose is oxidized in a controlled way to
release the energy stored in glucose in the form of ATP. It is an
energy-giving reaction.
6. Why do people get hot (and sweaty) during exercise?
7. Why do your muscles cramp up after a couple of minutes of all-out
sprinting?
Anaerobic exercise (no oxygen) causes acidification of muscle
cells during contractions. Acidification causes inactivation of
glycolytic enzymes.
, 8. Do vegans have cholesterol circulating in their veins?
Yes, besides taking up dietary cholesteral, the body also
produces its own cholesterol (from liver)
9. Why is the egg yolk in a soft-boiled egg still runny, while the egg white
is hard?
Egg white contains predomantily proteins. These denature
irrevisibly after set in the lipid
10. Why does a diabetic loose consciousness upon injection of too
much insulin?
Insulin leads to fast uptake of glucose by muscle and fat cells.
Glucose is also the most important source of energy for the
brain. Too much insulin reduces blood glucose levels, thus
depriving the brain of fuel.
11. How do many Asians become lactose intolerant while many
Europeans do not?
After weening, humans generally loose the ability to proces
lactose because the enzyme lactase is no longer express. Asians
do not have this mutation
12. Why is white fat white and brown fat brown?
Brown fat contains mitochondria which are brown due to the
high content of iron-containing proteins. White adipocytes
contain almost no mitochondria.
13. Can we get fat from eating carbohydrates?
It is metabolized into lipids, which are stored in the liver.
14. When people gain weight, do their fat cells get bigger or do they
produce more of them?
Both: hypertrophy (lager cells) and hyperplasia (more cells)
15. Chimpanzees spent half their day chewing food. How can we do
this in less than an hour?
The diet of chimps is more fibrous and less calorie dense, most
of our food is cooked and thus pre-digiested, which facilitates
uptake of nutrients
16. What do you spread on a healthy sandwich, butter or
margarine?
Neither, both contain mainly saturated fats and therefore
contain many calories. Margarine contains trans-fats which are
not safe. Butter is a natural product that contains vitamins and
minreals, so in that way butter is better.
Can we get fat from eating carbohydrates?
A carbohydrate is a biological molecule consisting
of carbon (C), hydrogen (H) and oxygen (O) atoms, The term is most
common in biochemistry, where it is a synonym of 'saccharide', a group
that includes sugars, starch, and cellulose. In food science the term
carbohydrate often means any food that is particularly rich in the complex
carbohydrate starch and sugar such as bread, pasta, candy, jam and
desserts.
1. Nothing lasts forever. How long does a covalent bond in a DNA
molecule last?
If not forever, then a very, very long time
2. How do Italians traditionally make balsamic vinegar for a salad
dressing?
Balsamic viegar is produced by slow fermetation of a
concentration of the juice of cooked white gapes. In this process
acetate is produced.
3. What are the crunchy white little crystals in mature cheese?
Calcium lactate; micro-organisms produce lactate via glycolysis
and secrete it into the cheese.
4. What tastes sweeter, honey or table sugar?
Honey tastes sweeter because it contains free fructose (glucose
+ fructose)
5. How does the cell retrieve energy from the reaction: C6H12O6 + 6
O2 ! 6 CO2 + 6 H2O?
ATP is produced via a proces called intermediary metabolism.
During this proces glucose is oxidized in a controlled way to
release the energy stored in glucose in the form of ATP. It is an
energy-giving reaction.
6. Why do people get hot (and sweaty) during exercise?
7. Why do your muscles cramp up after a couple of minutes of all-out
sprinting?
Anaerobic exercise (no oxygen) causes acidification of muscle
cells during contractions. Acidification causes inactivation of
glycolytic enzymes.
, 8. Do vegans have cholesterol circulating in their veins?
Yes, besides taking up dietary cholesteral, the body also
produces its own cholesterol (from liver)
9. Why is the egg yolk in a soft-boiled egg still runny, while the egg white
is hard?
Egg white contains predomantily proteins. These denature
irrevisibly after set in the lipid
10. Why does a diabetic loose consciousness upon injection of too
much insulin?
Insulin leads to fast uptake of glucose by muscle and fat cells.
Glucose is also the most important source of energy for the
brain. Too much insulin reduces blood glucose levels, thus
depriving the brain of fuel.
11. How do many Asians become lactose intolerant while many
Europeans do not?
After weening, humans generally loose the ability to proces
lactose because the enzyme lactase is no longer express. Asians
do not have this mutation
12. Why is white fat white and brown fat brown?
Brown fat contains mitochondria which are brown due to the
high content of iron-containing proteins. White adipocytes
contain almost no mitochondria.
13. Can we get fat from eating carbohydrates?
It is metabolized into lipids, which are stored in the liver.
14. When people gain weight, do their fat cells get bigger or do they
produce more of them?
Both: hypertrophy (lager cells) and hyperplasia (more cells)
15. Chimpanzees spent half their day chewing food. How can we do
this in less than an hour?
The diet of chimps is more fibrous and less calorie dense, most
of our food is cooked and thus pre-digiested, which facilitates
uptake of nutrients
16. What do you spread on a healthy sandwich, butter or
margarine?
Neither, both contain mainly saturated fats and therefore
contain many calories. Margarine contains trans-fats which are
not safe. Butter is a natural product that contains vitamins and
minreals, so in that way butter is better.
