AP Bio Lab #5
Cellular Respiration

 The process by which plant tissue expands in tight places involves water uptake through osmosis and imbibition , and an overall increase in size by cell division. In the case of an oak or pine tree splitting open a granite boulder, the amazing process starts with a seed that becomes lodged in a tiny crevice. Like a living, expanding wedge driven deeper and deeper into the crack, the boulder is literally forced apart by tremendous pressures.

Seed
Structure
A seed consists of three parts:
1) a Dormant
Embryo ,
2) a Storage
Tissue ,
3) a Seed Coat .

Seed
Structure
A seed consists of three parts:
1) a Dormant
Embryo ,
2) a Storage
Tissue ,
3) a Seed Coat .

Seed
Structure
A seed consists of three parts:
1) a Dormant
Embryo ,
2) a Storage
Tissue ,
3) a Seed Coat .

No seed germinates, unless it
absorbs water (imbibition)

Water hydrates an enzyme before water absorption after water absorption

abscisic acid, plant hormone
, keeps the embryo dormant (inhibits seed germination)

Water hydrates an enzyme
 This enzyme breaks down
(metabolizes) abscisic acid

Germination & subsequent growth require A GREAT DEAL
OF ENERGY
Young plants get this ENERGY by converting the energy of food molecules (starch in endosperm or cotyledon) to ATP during CELLULAR
RESPIRATION

O
2 enters the mitochondria
ATP is generated
(made)
CO
2 exits the mitochondria

When you study the equation for cellular respiration, you will see that there are at least three ways to measure RATE:
1. Measure the amount of glucose consumed.
2. Measure the amount of oxygen consumed.
3. Measure the amount of carbon dioxide produced.
In this experiment, we are going to measure the amount of oxygen consumed.

You will use a RESPIROMETER

CO
2

Determine the rate of O
2 consumption

 Y = change in volume
 X = change in time

 Y = change in volume
.24mL - .06mL = .16

 Y = .16 mL
 X = 10 min

 Y
 X
= .016 ml / min