Chapter 2.9 Photosynthesis

Question 1

Photosynthesis

Answer 1

the production of carbon compounds in cells using light energy

Question 2

Possible limiting factors on the rate of photosynthesis

Answer 2

Temperature, light intensity and carbon dioxide concentration

Question 3

Paper chromatography

Answer 3

a procedure that can separate the pigments present in most modern plants. The pigment chlorophyll “a” is the principal pigment. Chlorophyll “b” carotenes and xantophylls act as accessory pigments by absorbing light at different wavelengths, and passing this energy on to chlorophyll “a” to be used in photosynthesis.

Question 4

2 things a substance can do when struck by a particular wavelength of light

Answer 4

• absorb that wavelength (if so, energy is being absorbed and may be used)
• reflect that wavelength (if so, the energy is not being absorbed and you will see that color)

Question 5

Photosynthesis occurs in 2 stages

Answer 5

• produces sugar molecules as a food source for the plant. Sugars, such as glucose, are held together by covalent bonds. Requires energy to create those covalent bonds, source of energy from the Sun.
• 1st stage is a set of reactions that trap light energy and convert it to the chemical energy of ATP.
• 2nd stage is a set of reactions in which ATP is used to help bond carbon dioxide and water molecules together to create a sugar, such as glucose.

Question 6

1st stage of photosynthesis

Answer 6

light dependent reactions. chlorophyll and other photosynthetic pigments absorb light energy and convert that energy to a form of chemical energy, ATP. Light energy is used to accomplish a reaction that is called the photolysis of water. A water is split into its component elements: hydrogen and oxygen. Oxygen that is split away is released as a waste product. The useful products formed are ATP and HYDROGEN.

Question 7

2nd stage of photosynthesis

Answer 7

series of reactions referred to as the light independent reactions. ATP and hydrogen are used as forms of chemical energy to convert carbon dioxide and water into useful organic molecules for the plant. Glucose, a typical product of photosynthesis, is an organic molecule, it requires 6 inorganic carbon dioxide molecules to form 1 glucose molecule. This conversion of an inorganic form of an element to an an organic form is known as fixation. Therefore photosynthesis can be described as a series of reactions in which carbon dioxide and water are fixed into glucose, and oxygen is produced as a by-product.