The student is expected to: 4B investigate and explain cellular processes, including homeostasis, energy conversions, transport of molecules, and synthesis of new molecules and 9A compare the structures and functions of different types of biomolecules, including carbohydrates, lipids, proteins, and nucleic acids.

KEY CONCEPT All cells need chemical energy.

The chemical energy used for most cell processes is carried by ATP. Molecules in food store chemical energy in their bonds. Starch molecule Glucose molecule

KEY CONCEPT The overall process of photosynthesis produces sugars that store chemical energy.

Photosynthetic organisms are producers. Producers make their own source of chemical energy. Plants use photosynthesis and are producers. Photosynthesis captures energy from sunlight to make sugars.

Chlorophyll is a molecule that absorbs light energy. chloroplast leaf cell leaf In plants, chlorophyll is found in organelles called chloroplasts. chloroplast stroma grana (thylakoids)

The equation for the overall process is: 6CO2 + 6H2O  C6H12O6 + 6O2 C6H12O6 granum (stack of thylakoids) thylakoid sunlight 1 six-carbon sugar 6H2O 6CO2 6O2 chloroplast 1 2 4 3 energy stroma (fluid outside the thylakoids)

KEY CONCEPT The overall process of cellular respiration converts sugar into ATP using oxygen.

Cellular respiration makes ATP by breaking down sugars. Cellular respiration is aerobic, or requires oxygen. Aerobic stages take place in mitochondria. mitochondrion animal cell

Glycolysis must take place first. anaerobic process (does not require oxygen) takes place in cytoplasm splits glucose into two three-carbon molecules produces two ATP molecules

Cellular respiration is like a mirror image of photosynthesis. The equation for the overall process is: C6H12O6 + 6O2  6CO2 + 6H2O The reactants in photosynthesis are the same as the products of cellular respiration.