Cellular Energy

CHAPTER 8

REVIEW

What is energy?

Can energy be created?

What are some forms of energy?

Why do living things need energy?

How do humans obtain energy?

THE PHOTOSYNTHESIS EQUATION

6 C02 + 6 H2O C6H12O6 + 6 O2

Carbon + water sugars + oxygen dioxide

Photosynthesis uses the energy from sunlight to convert water and carbon dioxide into high-

energy sugars and oxygen.

LIGHT

HOW ORGANISMS OBTAIN ENERGY

All cellular activities require ENERGY

Energy is the ability to do work

Assembly of macromolecules

Break down of macromolecules

Cell transport

Transport of genetic information

TRANSFORMATION OF ENERGY

Law of Thermodynamics –studies the flow of energy

First Law - Conservation of energy energy can be converted from one form to another,

but it cannot be created or destroyed

Second Law of thermodynamics Energy is not converted without some loss of useable

energy, typically thermal energy

AUTOTROPHS AND HETEROTROPHS

Autotrophs – make their own food; most convert light energy to food

Chemotrophs – use inorganic substances as a source of energy

Heterotroph – organisms that need to ingest food to obtain energy

METABOLISM

Metabolism – ALL the chemical reactions in a cell

Two types of metabolic pathways:

Catabolic – release energy by breaking down larger molecules into smaller molecules

Anabolic – use energy to build larger molecules from smaller molecules

METABOLISM

Photosynthesis –

Anabolic pathway in which light energy from the sun is converted to chemical energy for use by the body

Cellular Respiration –

Catabolic pathway in which organic molecules are broken down to release energy

METABOLISM

Photosynthesis

6 C02 + 6 H2O C6H12O6 + 6 O2

Reactants Products

Cellular Respiration

6 O2 + C6H12O6 6 H2O + 6 C02

ENERGY FLOW

Photosynthesis(autotrophs)

Cellular Respiration (heterotrophs)

C6H12O6 + 6 O26 C02 + 6 H2O

ATP

ATP = ADENOSINE TRIPHOSPHATE

ATP ATP provides chemical energy for cells

Composed of –

Adenine Base

Ribose Sugar

Three Phosphate Groups

ATP

ATP

Energy is STORED in the chemical bonds between phosphate groups

Energy is RELEASED when the bond between the second and third phosphate group is broken

ATP/ADP

ATP releases energy when the bond between the second and third phosphate group is broken

This forms ADENOSINE DIPHOSPHATE (ADP)

Energy is stored in the phosphate bond when ADP receives a phosphate group to become ATP

ATP/ADP

Phosphate Groups

Phosphate Groups

LIGHT ENERGY AND PIGMENT

LESSON OBJECTIVES

Students will be able to:

1. Explain that white light is composed of multiple colors.

2. Understand that different colors of light have different wavelengths (λ) and different amounts of energy (E).

3. List the colors of the visible light spectrum.

4. Identify which color of light has the most energy/least energy.

THE ENERGY OF LIGHT

VISIBLE LIGHT SPECTRUM

Sunlight is composed of colors with different wavelengths

ROY G BIV

Longer wavelengths (red/orange) have lower energy than shorter wavelengths (violet/indigo)

E = hc/λ

where E = energy, h = Planck’s constant, c = speed of light, and λ = wavelength

ELECTROMAGNETIC SPECTRUM

LESSON 2: OBJECTIVES

Students will be able to:

1. Define work.

2. Understand that light energy can be converted into other forms of energy.

3. Explain the THREE options for light energy when it meets an object.

4. Define pigment.

5. Identify THREE pigments found in plants and tell which colors of light each pigment absorbs.

LIGHT DOES WORK!

Work – force times the distance through which it acts.

W = F x d

Can light do work?

Crookes Radiometer Video

Absorbed

Reflected

Transmitted

PLANT PIGMENT CHROMATOGRAPHY

HOMEWORK:

Lab tomorrow – requires goggles and apron

Read laboratory packet

View pre-lab video on YouTubehttp://www.youtube.com/watch?v=THqmpLdUaBA&feature=related

WORK CITED

"Electromagnetic Spectrum." 25 January 2010 <http://www.optics.arizona.edu/Nofziger/UNVR195a/Class12/EMspectrum1.gif>.

Ronk. "My Perpetual Motion Machine." 20 September 2009. Weekends in Paradelle. 27 January 2010 <http://paradelle.files.wordpress.com/2009/09/crookes_radiometer.jpg?w=210&h=273>.

"work." The American Heritage® New Dictionary of Cultural Literacy, Third Edition. Houghton Mifflin Company, 2005. 26 Jan. 2010. <Dictionary.com http://dictionary.reference.com/browse/work>.