1. Cell Processes and Energy
Chapter 3

2. Chemical Compounds in Cells
Section 1

3. Big Question
What do all living things have in common?

4. Big Answer
All living things carry out the same life processes of nutrition, gas exchange, response, reproduction, removal of waste, and growth and repair.
All living things need water to live.
All living things contain the compounds carbohydrates, lipids, proteins, and nucleic acids.

5. Carbohydrates
A carbohydrate is an energy-rich organic compound made of the elements carbon, hydrogen, and oxygen.
Sugars and starches are carbohydrates.

6. Lipids
Lipids are energy-rich organic compounds made of carbon, hydrogen, and oxygen and contain more energy than carbohydrates.
Lipids are used to store energy.

7. Proteins
Proteins are large organic molecules made of carbon, hydrogen, oxygen, nitrogen, and in some cases, sulfur.
Protein molecules are made up of smaller molecules called amino acids.
An enzyme, a type of protein, speeds up chemical reaction in a living thing.

8. Nucleic Acid
Nucleic acids are very long organic molecules made of carbon, oxygen, hydrogen, nitrogen, and phosphorus.
They contain the instructions that cells need to carry out all the functions of life.

9. The Cell in its Environment
Section 2

10. Big Question
How do substances move in and out of cells?

11. Big Answer
Substances move in and out of cells through the processes of diffusion, osmosis, and active and passive transport.

12. Diffusion
Diffusion is the main method by which small molecules move across the cell membrane.
Diffusion is the process by which molecules move from an area of higher concentration to an area of lower concentration.

13. Osmosis
Osmosis is the diffusion of water molecules through a selectively permeable membrane.
Because cells cannot function properly without adequate water, many cellular processes depend on osmosis.

14. Active and Passive Transport
Active Transport
Passive Transport
Active transport is the movement of materials through a cell membrane using cellular energy.
Transport proteins pick up molecules outside the cell and carry them in.
Transport by Engulfing
Passive transport is the movement of dissolved materials through a cell membrane without using cellular energy.
Diffusion
Osmosis

15. Photosynthesis
Section 3

16. Big Question
How do different types of cells take in food ?

17. Big Answer
Nearly all living things obtain energy either directly or indirectly from the energy of sunlight captured during photosynthesis.
Autotrophs are organisms that make their own food.
Heterotrophs are organisms that cannot make their own food.
Eat other organisms.
Absorb food from other organisms.

18. Photosynthesis 6CO2 + 6H2 O C6H12O6 + 6O2
During photosynthesis, plants and some other organisms use energy from the sun to convert carbon dioxide and water into oxygen and sugars.
Stage 1 – Capturing the Sun’s Energy
Stage 2 – Using Energy to Make Food
6CO2 + 6H2 O
C6H12O6 + 6O2
Light energy

19. Respiration
Section 4

20. Big Question
How do cells receive energy?

21. Big Answer
Cells receive energy through respiration when cells break down simple food molecules such as sugar and release the energy they contain.

22. Respiration C6H12O6 + 6O2 6CO2 + 6H2 O
Stage 1 – In the cytoplasm molecules of glucose are broken down into smaller molecules.
Stage 2 – In the mitochondria small molecules are broken down into even smaller molecules.
C6H12O6 + 6O2
6CO2 + 6H2 O

23. Big Question – for you to answer
What is the relationship between respiration and photosynthesis?

24. Fermentation
Fermentation is an energy releasing process that does not require oxygen.
The amount of energy released is much smaller.

25. Cell Division
Section 5

26. Big Question
How and why do cells divide?

27. Big Answer
Cells grow and divide in the cell cycle. During this cycle cells divide. Cells divide to produce new cells.

28. Cell Cycle Stage 1 – Interphase Stage 2 – Mitosis
During interphase, the cell grows, makes a copy of its DNA, and prepares to divide into two cells.
Replication is the process in which the cell makes an exact copy of the DNA in its nucleus.
Stage 2 – Mitosis
During mitosis, one copy of the DNA is distributed into each of the two daughter cells.
Stage 3 – Cytokinesis
During cytokinesis, the cytoplasm divides. The organelles are distributed into each of the two new cells.