PLTW Biomedical Science Final Study
Guide
What is a calorie? - Correct Answers -A unit of heat energy
With our crude calorimeters in class we burned food by lighting it on fire. What chemical
reaction occurs when food is burned? How does this reaction relate to the breakdown of
food for energy in our body? - Correct Answers -A combustion reaction occurs. The
food and oxygen in the air combine to form carbon dioxide and water molecules and
produce lots of energy. This happens in the body as well, using enzymes to catalyze all
of the reactions.
If you burned a sample of food and the temperature of 100g of water in your calorimeter
rose from 20oC to 36oC, how many calories were in the food sample?
Calories = (specific heat of water) x (change in temp of water) x (mass of water) Specific
heat of water = 1 calorie/goC - Correct Answers -Calories = (1 cal/goC) (16oC) (100g) =
1600 calories
If the food sample you burned above had a mass of 10g before burning and 8g after
burning, how many calories/gram did the food contain? - Correct Answers -1600
calories/2g = 800 calories/gram
We are expressing our calories calculated above as chemistry calories. How are food
calories different? - Correct Answers -1 food Calorie = 1000 chemistry calories
Which macromolecules -- carbohydrates, proteins or lipids - have the highest
calories/gram? - Correct Answers -Lipids have the highest: 9 Calories/gram.
In our bodies the food we eat is broken down into its building blocks as it passes
through our digestive system. Answer the following questions about this process:
Where does digestion begin? - Correct Answers -In the mouth with active chewing and
the enzymes in saliva.
The enzymes amylase and lipase are found in saliva. Which macromolecules do these
enzymes break down? - Correct Answers -Amylase breaks down carbohydrates. Lipase
breaks down lipids.
, Cardiologist - Correct Answers -Doctor who specializes in care of the heart and
cardiovascular system. Performs cardiac work-ups, analyzes tests such as EKGs and
performs heart surgeries such as angioplasty and stent placement.
Epidemiologist - Correct Answers -An epidemiologist studies outbreaks (or epidemics).
They are public health officials and they can work for the government, trying to identify
and isolate patients affected by a disease outbreak. They might work to identify disease
treatments.
Microbiologist - Correct Answers -Microbiologists study microorganisms and often do
research for universities. They can also work in a hospital, identifying pathogens
contracted by patients.
Physical therapist: - Correct Answers -Aid patients in recovery from injury, surgery, or
amputation by guiding them in physical exercises and stretching to make muscles
strong and keep joints limber.
In the stomach, lipase and pepsin are secreted. Which macromolecule does pepsin
break down? - Correct Answers -Pepsin breaks down proteins.
What substance is made in the liver and stored in the gall bladder? What does it do? -
Correct Answers -Bile: it helps to dissolve (emulsify) lipids
The duodenum is part of which organ in the digestive system? - Correct Answers -The
small intestine
Several enzymes are secreted into the duodenum, including trypsin and chymotrypsin.
Which macromolecule do these enzymes break down? - Correct Answers -Trypsin and
chymotrypsin break down proteins.
Besides digestion in the first part of the small intestine, what is the major role for the rest
of the small intestine? - Correct Answers -Absorption of nutrients into the bloodstream.
What happens in the large intestine to the remaining digested food? - Correct Answers -
Water is removed from the food in the large intestine.
The building blocks of the macromolecules are further broken down through the
catabolic pathway in our cells. Answer the following questions about this metabolic
pathway:
What is our primary source of energy? What macromolecule does it come from? -
Correct Answers -Glucose. Glucose comes from starch, a carbohydrate polymer.
What is the end product of the energy producing catabolic pathway? - Correct Answers
-ATP
Guide
What is a calorie? - Correct Answers -A unit of heat energy
With our crude calorimeters in class we burned food by lighting it on fire. What chemical
reaction occurs when food is burned? How does this reaction relate to the breakdown of
food for energy in our body? - Correct Answers -A combustion reaction occurs. The
food and oxygen in the air combine to form carbon dioxide and water molecules and
produce lots of energy. This happens in the body as well, using enzymes to catalyze all
of the reactions.
If you burned a sample of food and the temperature of 100g of water in your calorimeter
rose from 20oC to 36oC, how many calories were in the food sample?
Calories = (specific heat of water) x (change in temp of water) x (mass of water) Specific
heat of water = 1 calorie/goC - Correct Answers -Calories = (1 cal/goC) (16oC) (100g) =
1600 calories
If the food sample you burned above had a mass of 10g before burning and 8g after
burning, how many calories/gram did the food contain? - Correct Answers -1600
calories/2g = 800 calories/gram
We are expressing our calories calculated above as chemistry calories. How are food
calories different? - Correct Answers -1 food Calorie = 1000 chemistry calories
Which macromolecules -- carbohydrates, proteins or lipids - have the highest
calories/gram? - Correct Answers -Lipids have the highest: 9 Calories/gram.
In our bodies the food we eat is broken down into its building blocks as it passes
through our digestive system. Answer the following questions about this process:
Where does digestion begin? - Correct Answers -In the mouth with active chewing and
the enzymes in saliva.
The enzymes amylase and lipase are found in saliva. Which macromolecules do these
enzymes break down? - Correct Answers -Amylase breaks down carbohydrates. Lipase
breaks down lipids.
, Cardiologist - Correct Answers -Doctor who specializes in care of the heart and
cardiovascular system. Performs cardiac work-ups, analyzes tests such as EKGs and
performs heart surgeries such as angioplasty and stent placement.
Epidemiologist - Correct Answers -An epidemiologist studies outbreaks (or epidemics).
They are public health officials and they can work for the government, trying to identify
and isolate patients affected by a disease outbreak. They might work to identify disease
treatments.
Microbiologist - Correct Answers -Microbiologists study microorganisms and often do
research for universities. They can also work in a hospital, identifying pathogens
contracted by patients.
Physical therapist: - Correct Answers -Aid patients in recovery from injury, surgery, or
amputation by guiding them in physical exercises and stretching to make muscles
strong and keep joints limber.
In the stomach, lipase and pepsin are secreted. Which macromolecule does pepsin
break down? - Correct Answers -Pepsin breaks down proteins.
What substance is made in the liver and stored in the gall bladder? What does it do? -
Correct Answers -Bile: it helps to dissolve (emulsify) lipids
The duodenum is part of which organ in the digestive system? - Correct Answers -The
small intestine
Several enzymes are secreted into the duodenum, including trypsin and chymotrypsin.
Which macromolecule do these enzymes break down? - Correct Answers -Trypsin and
chymotrypsin break down proteins.
Besides digestion in the first part of the small intestine, what is the major role for the rest
of the small intestine? - Correct Answers -Absorption of nutrients into the bloodstream.
What happens in the large intestine to the remaining digested food? - Correct Answers -
Water is removed from the food in the large intestine.
The building blocks of the macromolecules are further broken down through the
catabolic pathway in our cells. Answer the following questions about this metabolic
pathway:
What is our primary source of energy? What macromolecule does it come from? -
Correct Answers -Glucose. Glucose comes from starch, a carbohydrate polymer.
What is the end product of the energy producing catabolic pathway? - Correct Answers
-ATP
