| 
  • If you are citizen of an European Union member nation, you may not use this service unless you are at least 16 years old.

  • You already know Dokkio is an AI-powered assistant to organize & manage your digital files & messages. Very soon, Dokkio will support Outlook as well as One Drive. Check it out today!

View
 

Botany Chapter 5

Page history last edited by Shelly Turner 11 years, 6 months ago

Chapter 5:  Photosynthesis and Cellular Respiration

 

 

Using your vocabulary words, make notecards/flashcards that you can use outside of class to study. 

 

Work on your Directed Reading in class every chance you get.  Remember that I will assist you on the harder questions.  This assignment is due the day we take the test on this chapter.  Use the information in this assignment as a study guide for your test.

This study guide is to help you study for your test.  It should not be the only item you use to study w hen preparing for the test.  Remember to complete your Directed Reading for every chapter along with writing your vocabulary words on notecards to help you remember them.  And always remember to listen carefully in lecture because all of the information in this study guide will be covered.

 

Chapter 5 Coloring Lab 

 

I.       Energy Flow  - Directly or indirectly, almost all of the energy in living systems needed for metabolism comes from the sun.        

A.   Autotrophs – harness energy from sunlight

1.     photosynthesis – process located in the chlorophyll by which light energy is converted into chemical energy and stored in organic compounds

2.     cellular respiration – metabolic process located in the mitochondria that releases energy from organic compounds for immediate use

B.    Heterotrophs – must consume food for energy; use cellular respiration to release the energy from the organic compounds in that food

 

5-60014.swf 

 

C.    Building Molecules That Store Energy

1.    Metabolism involves either using energy to build molecules or breaking down molecules in which energy is stored.

2.    Photosynthesis is the process by which light energy is converted to chemical energy.

3.    Organisms that use energy from sunlight or from chemical bonds in inorganic substances to make organic compounds are called autotrophs.

D.    Breaking Down Food for Energy

1.    The chemical energy in organic compounds can be transferred to other organic compounds or to organisms that consume food.

2.    Organisms that must get energy from food instead of directly from sunlight or inorganic substances are called Heterotrophs.

3.    Cellular respiration is a metabolic process similar to burning fuel.

  

E.   ATP – adenosine triphosphate, “energy currency” of the cell; stores energy for later use; release of this energy results in ADP adenosine Diphosphate

1.     The formula for energy storage is as follows...

a)    ADP + Phosphate → ATP

2.     The formula for energy release is as follows…

a)  ATP – Phosphate → ADP + Energy 

b)  H2O + ATP → ADP + P + energy

 

Transfer of Energy to ATP

  • When cells break down food molecules, some of the energy in the molecules is released as heat. Much of the remaining energy is stored temporarily in molecules of ATP.
  • Like money, ATP is a portable form of energy “currency” inside cells. ATP delivers energy wherever energy is needed in a cell.

ATP

  • ATP (adenosine triphosphate) is a nucleotide with two extra energy-storing phosphate groups.
  • Energy is released when the bonds that hold the phosphate groups together are broken.
  • The removal of a phosphate group from ATP produces adenosine diphosphate, or ADP

 

H2O + ATP → ADP + P + energy

 

II.    Photosynthesis

 

A.  The Steps of Photosynthesis 

Stage 1 Energy is captured from sunlight.

Stage 2 Light energy is converted to chemical energy, which is temporarily stored in ATP and the energy carrier molecule NADPH.

Stage 3 The chemical energy stored in ATP and NADPH powers the formation of organic compounds, using carbon dioxide, CO2.

 

Photosynthesis can be summarized by the following equation:

 

     6CO2      +            6H2O     +        SUNLIGHT       →       C6H12O6       +      6 O2

(carbon dioxide)     (water)                 (energy)                     (glucose)            (oxygen)

 

B.   Occurs in the chloroplast

 

5-60013.swf  

 

5-60094.swf

 

5-60105.swf

 

C.   Occurs in plants and in other autotrophs

 

     6CO2      +            6H2O     +        SUNLIGHT       →       C6H12O6       +      6 O2

(carbon dioxide)     (water)                 (energy)                     (glucose)            (oxygen)

 

5-60091.swf

 

5-60092.swf

 

D.   Occurs in two steps

1.     Light Reactions

a)    Sun activates chlorophyll to trap energy

b)    Water is split into hydrogen (H) and oxygen (O2)

c)    H is trapped by NADP (electron carrier) to create NADPH (high energy electron carrier)

d)    Excess energy is stored in ATP

2.     Dark Reactions

a)    Carbon dioxide (CO2) is trapped by a five carbon sugar (RuBP) creating ultimately 2 molecules of a three carbon sugar (PGA)

b)    PGA reacts with H forming food for the plant (PGAL) which may be used to form food for us (glucose -   C6H12O6)

E.   Production of Oxygen 

1.  Clusters of pigments are embedded in the membranes of disk-shaped structures called thylakoids.
2.  When light strikes a thylakoid in a chloroplast, energy is transferred to electrons in chlorophyll.
3.  This energy transfer causes the electrons to jump to a higher energy level. This is how plants first capture energy from sunlight.
4.  The excited electrons that leave chlorophyll molecules must be replaced by other electrons.
5.  Plants get these replacement electrons from water molecules, which are split by thylakoid.
6.  The oxygen atoms, O, from the disassembled water molecules combine to form oxygen gas, O2.  

III.   Cellular Respiration

A.   Occurs in heterotrophs and autotrophs

 

C6H12O6  +  6 O2   →       6CO+ 6H2O +  38ATP

     (glucose)         (oxygen)       (carbon dioxide)     (water)       (energy)

 

5-60107.swf

 

B.   Two Stages:

1.     Stage 1- Glycolysis – occurs in the cytoplasm; breaks down glucose onto pyruvates and releases a small amount of ATP (does not require oxygen)

2.     Stage 2 – occurs in the mitochondria; is more efficient and recovers a greater amount of energy then stage 1 ( there are two possibilities or “pathways”)

a)    Krebs’s Cycle/Chemiosmosis – (aerobic) happens in the presence of oxygen, produces total of 38 ATP

 

5-60111.swf

 

5-60114.swf

 

b)    Fermentation – (anaerobic) happens in the absence of oxygen; produces a total of only 2 ATP

 

Pigments

 

How does a human eye or a leaf absorb light? These structures contain light-absorbing substances called pigments.

Chlorophyll the primary pigment involved in photosynthesis, absorbs mostly blue and red light and reflects green and yellow light.

Plants contain two types of chlorophyll, chlorophyll a and chlorophyll b.

 

The pigments that produce yellow and orange fall leaf colors, as well as the colors of many fruits, vegetables, and flowers, are called carotenoids.

Carotenoids absorb wavelengths of light different from those absorbed by chlorophyll, so having both pigments enables plants to absorb more light energy during photosynthesis.

 

5-60093.swf

 

 

 

Comments (0)

You don't have permission to comment on this page.