Science Exam

Question 1

1. food provides…

Answer 1

energy and building materials for cells

Question 2

Oxygen

Answer 2

O₂
Used for cellular respiration. Produced in Photosynthesis.

Question 3

Carbon Dioxide

Answer 3

CO₂
Used for photosynthesis. Produced in cellular respiration.

Question 4

2. different types of food molecules, when reacting with oxygen, produce…

Answer 4

different amounts of energy

Question 5

Water

Answer 5

H₂O
Used for photosynthesis. Produced in cellular respiration.

Question 6

Glucose

Answer 6

CHO
Used for cellular respiration. Produced in photosynthesis. Energy molecules in food. Example: Carbohydrates

Question 7

3. the difference in the amount of energy that carbohydrates, proteins, and fats have the capacity to provide is due to…

Answer 7

the differences in the arrangement and number of different types of atoms in the molecules

Question 8

4. large food molecules are broken down through…

Answer 8

a chemical reaction

Question 9

Starch

Answer 9

Examples: C₆H₁₂O₆
Consists of a large number of glucose subunits. How glucose is stored in plants.

Question 10

5. organisms build up new molecules through a chemical reaction. these molecules are used for growth and repair. when food molecules are not used immediately, organisms can…

Answer 10

store them for short or long periods of time for energy or to be used as building materials.

Question 11

Carbohydrates

Answer 11

Sugar and Starch. Molecules containing C₆H₁₂O₆
-Same number of carbon & Oxygen
-Twice as many hydrogens
-Carbohydrates 4 calories per 1 gram
-Provides body less energy than fat
-IQWST book PG. 41,59

Question 12

6. plants need …………. to grow

Answer 12

water and light

Question 13

7. plants convert ………. into ………

Answer 13

light energy into chemical energy

Question 14

Proteins

Answer 14

Contains C, H, O, N
Sometimes Sulfur
Alanine- C₃H₇NO₂
-Combined amino acid subunits
-Proteins 4 calories per 1 gram
-Provides body less energy than fat
-IQWST book PG. 41,61

Question 15

8. photosynthesis is a chemical reaction that…

Answer 15

uses energy from the sun and the reactants carbon dioxide and water to form glucose and molecules of oxygen

Question 16

9. burning food requires …….. and produces ………. In the process, ……….. is released.

Answer 16

food molecules and oxygen produces carbon dioxide and water. In the process, energy is released. >0<

Question 17

Fats

Answer 17

C₅₆H₁₁₀O₆
-Made up of molecules called triglycerides
-IQWST book PG. 61,41,63

Question 18

10a. cellular respiration is…

Answer 18

the chemical reaction that provides energy to the cells of an organism

Question 19

10b. during cellular respiration, organisms…

Answer 19

use oxygen and food molecules and produce water and carbon dioxide

Question 20

Photosynthesis

Answer 20

6CO₂+6H₂O→C₆H₁₂O₆+6O₂
Carbon dioxide gas molecules are combined with six molecules of liquid water to produce six molecules of oxygen gas and molecules of glucose.

Question 21

Cellular Respiration

Answer 21

C₆H₁₂O₆+6O₂→6CO₂+6H₂O
Glucose molecules are combined with oxygen gas molecules to form six molecules of carbon dioxide gas and six molecules of water.

Question 22

Plants in the light

Answer 22

Photosynthesis
6CO₂+6H₂O→C₆H₁₂O₆+6O₂
C₆H₁₂O₆+6O₂→6CO₂+6H₂OActivity 7.1 Plants in light tested positive for starch molecules,
plants in the light did not, plants in light produced O2 molecules,
plants in the dark did not. In Activity 7.2 PlantsTubestube with
bromothymol blue (BTB) solution had a color change, from yellow to
blue, in light demonstrating loss of CO2 from solution.
We used logic to infer how the plants stay alive during the night.

Question 23

Plants in the dark

Answer 23

Cellular resperation
C₆H₁₂O₆+6O₂→6CO₂+6H₂O
In Activity 9.2 plants in the dark did show a loss of CO₂. Plants in dark changed color from blue to yellow demonstrating the production of CO₂.

Question 24

Burning of food in the laboratory

Answer 24

C₆H₁₂O₆+6O₂→6CO₂+6H₂O+light and heat energy
Activity 8.1 Decrease in O₂ concentration, and increase in CO₂ concentration in ppm. Observations of light energy.

Question 25

Using food in the human body for energy

Answer 25

C₆H₁₂O₆+6O₂→6CO₂+6H₂O+Heat energy
Above → is Enzymes
Activity 1.1 Increases in CO₂ concentration in ppm, increased breathing rate. Activity 8.1 increases CO₂ concentration, decreases O₂ concentration, and increases in absolute humidity.

Question 26

Application Idea #1: O₂ AND CO₂ LEVELS
What happens to the oxygen and carbon dioxide in our blood when people exercise?

Answer 26

1. levels of oxygen increase
2. levels of carbon dioxide decrease

Reasoning:
When exercising, breath rate increases b/c more oxygen is inhaled so that energy can be made faster. As a result of this, more oxygen is inhaled faster, and more carbon dioxide is produced by being exhaled more.

Question 27

Application Idea #2: FRENCH FRY
What happens when you digest a French fry? (French fries are made from potatoes which are full of starch molecules)

Answer 27

When a French fry is digested:
1. it has been broken down from starch (polysaccharides) to glucose molecules (monosaccharides)
2. glucose + oxygen travels through the circulatory system to all cells to provide us w/ energy

Question 28

Application Idea #3: WILLOW TREE WEIGHT
A 5-pound willow tree is planted in a pot with nutrient-rich soil. The plant is left outside in the sun, and each month it is watered with 1 gallon of water. Five years later, the plant is taken out of the pot and the tree is found to weigh 170 pounds. Where did these 165 pounds come from?

Answer 28

CO₂ + water are used to make more glucose molecules that stay in the plant and cause an increase in mass from adding carbon to the plant.

Question 29

What chemical reaction breaks down food molecules into sub-units?

Answer 29

Hydrolysis combines water and large food molecules to create sub-units
Example:
A carbohydrate with many subunits+ Many molecules of water→ Many Carbohydrate subunits

Question 30

what chemical reaction combines sub-units into larger molecules?

Answer 30

Dehydration synthesis removes water
Example:
Two amino acids → molecules with 2 amino acids+ water

Question 31

Based on laboratory activities #1.1 and 1.2, what claim can you make about how your body uses energy when you exercise?

Answer 31

PG. 11
-increase in the amount of activity causes changes we observed when we exercised in class.
-heart beat faster, breathed faster, breathed more carbon dioxide, skin temp. decreased
PG. 9
-Energy can make things happen simplest way to talk
about it. There are many types of energy, such as light, thermal, kinetic, elastic, and sound.

Question 32

Based on activity 2.2, what claim can you make about the conditions or materials that plants need to grow?

Answer 32

PG.30
data from investigation provided evidence humans can get energy from eating plants, the tortilla chips activity illustrated. Your body converts chemical energy stored in plant into energy your cells can use. Therefore, by studying plants, how they get energy, you learn about how get energy you need. We set an experiment test plants need light, water, soil grow and produce food. We collected data which organized and written about CER for Activity 6.1. Our data demonstrated plants we grew needed light not just heat energy, the plants in dark not grow well as the plants in light, even though they at the same temperature. In addition, plants grew best in white light, blue light, red light, while plants in green light turn yellow, died. This demonstrates plants need certain colors light to grown. Our data shows plants need water to grow as plants without water died. The plants in soil, vermiculate (without soil) grew same indicating plants don’t need soil to grow.

Question 33

Based on activity 3.1, what claim can you make about why different food molecules provide different amounts of energy? (You can focus on Marshmallows, Cheese puffs, and vegetable oil.)

Answer 33

PG. 63
you look Venn diagram, you see carbohydrates, proteins have about same number carbon, oxygen atoms, twice as many hydrogen atoms.

Glucose, a carbohydrate, 6 carbon atoms, 6 oxygen atoms, and 12 hydrogen atoms make C6H12O6. Fats have few oxygen atoms compared to carbon atoms. The chemical formula the triglyceride shown in reading is C56H110O6. Difference the number of oxygen atoms reason fats provide body with more energy than carbohydrates and proteins.

Question 34

Based on activity 4.1, what claim can you make about how our body changes carbohydrates into building materials?
(Be sure to address the idea of an enzyme in your answer.)

Answer 34

PG. 78
-One molecule of starch=thousands of carbohydrate subunits
-chemical reaction, carbohydrate made of two subunits splits between the two subunits. One of the hydrogen atoms from water molecule separates from water molecule and combines with one subunit.
-other oxygen atom
and hydrogen atom from that same water molecule combine with the other subunit.
-When starch breaks down, it turns into carbohydrate subunits. These subunits are new molecules that form a new substance glucose which has very different properties than starch.

PG. 81
Organisms need to break down food molecules for two reasons.
-complex food molecules
are too big to fit inside of cells, but the subunits can easily get into a cell. Once the food molecule is in the cell,
it can go through more chemical reactions to be used for energy and building materials.
-different organisms need different kinds of carbohydrates and proteins.
-when you eat an egg, you are
eating the proteins that are important for chickens. However, you do not need chicken proteins to live. You
need human proteins. Those chicken proteins must be broken down into their subunits so that your body can
make a protein that is useful for you

laboratory activity, we measured that starch had changed into glucose in the presence of the enzyme amalyse. We confirmed this by testing for glucose using Benedict’s indicator and found glucose in the starch solution containing enzyme and no glucose in the starch solution without enzyme. This helps us see that food molecules are broken down into sub-units for our body to use for energy or building materials.

Question 35

Based on the activities and readings in lesson 10, describe how carbon cycles and energy flow between humans and plants.

Answer 35

1. animals and/or plants exhale CO₂ (b/c of cellular respiration)
2. Plants inhale CO₂ during photosynthesis
3. animals eat carbon-containing food molecules that plants make
4. carbon atoms are rearranged into carbon dioxide during cellular respiration (for both plants and animals)
   + Carbon atoms are rearranged into CO₂ during photosynthesis to make food molecules
5. Cycle repeats again with plants inhaling CO₂ (b/c of photosynthesis)

Question 36

Application Idea #4: CARBON ATOMS
This year on the 8th-grade trip we visited Mount Vernon, the home of George Washington. Explain how it is possible that carbon atoms that were once in the body of George Washington are now in your body.

Answer 36

1. George Washington exhaled carbon atoms
2. plants took in CO₂ molecules
3. plants use these molecules to make food molecules (CO₂ molecules used in photosynthesis)
4. CO₂ molecules are either inhaled b/c of plant’s cellular respiration or the plant (which took in the CO₂ molecules) was eaten

Conclusion: The CO₂ molecules that have been exhaled by George Washington cycle through the environment in multiple different ways, like being taken in by plants through photosynthesis and the plants being eaten and/or the plants exhaling CO₂ b/c of cellular respiration.