PHOTOSYNTHESIS & CELLULAR RESPIRATION

SC.912.L.18.9

Additional Site for EOC Help:http://www.ecsd-fl.schoolloop.com/biologyeocreview

PHOTOTSYNTHESIS

• Organisms need energy to survive. Some organisms are capable of absorbing energy from sunlight and using it to produce sugar.

• These organisms are called autotrophs, producers, or most plants.

PHOTOTSYNTHESIS• In photosynthesis, solar energy is converted to chemical

energy. The chemical energy is stored in the form of glucose (sugar). Carbon dioxide, water, and sunlight are used to produce glucose, oxygen, and water. The chemical equation for this process is:

6CO2 + 12H2O + light → C6H12O6 + 6O2 + 6H2O

6 molecules of carbon dioxide (6CO2) and 12 molecules of water (12H2O) are consumed in the process, while glucose (C6H12O6), six molecules of oxygen (6O2), and six molecules of water (6H2O) are produced.

• This equation may be simplified as:

6CO2 + 6H2O + light → C6H12O6 + 6O2

PHOTOSYNTHES & CELLULAR RESPIRATION

• The process of Photosynthesis and Respiration serve one another. While Photosynthesis requires carbon-dioxide and releases oxygen to produce glucose, Respiration needs oxygen while inhaling and releases carbon-dioxide while exhaling.

EQUATIONS FOR BOTH:

CELLULAR RESPIRATION• This energy is provided by the cells, and is produced when

the cells break down the chemical composition of food molecules and convert them into energy, i.e. convert glucose to energy. This is made possible with the process called cellular respiration, which takes place in the mitochondrion - the power house of a cell. During this process, cells break down glucose molecules and release energy. This energy that is released from the glucose is used to produce ATP. Therefore, cellular respiration is the process by which energy from glucose is transferred to ATP. It is a part of metabolism and all organisms go through cellular respiration.

CELLULAR RESPIRATION• We all need energy to function and we get

this energy from the foods we eat. The most efficient way for cells to harvest energy stored in food is through cellular respiration, a catabolic pathway for the production of adenosine triphosphate (ATP). ATP, a high energy molecule, is expended by working cells. Cellular respiration occurs in both eukaryotic and prokaryotic cells.

CELLULAR RESPIRATION• Aerobic respiration plays a crucial role in the

production of ATP, where glucose and oxygen are vital elements. This process takes place only if oxygen is available.

• C6H12O6 + 6O2 = 6CO2 + 6H2O + Energy (ATP)

ANAEROBIC CELLULAR RESPIRATION

• Anaerobic respiration is cellular respiration that occurs without oxygen. The process of anaerobic respiration begins with breaking down glucose (sugar molecules) that produces pyruvic acid.

THE ATP/ADP CYCLE

THE ATP/ADP CYCLE

• When a cell requires energy, the third phosphate separates from ATP and energy is released. The resulting molecule, ADP, is recyclable , able to accept and store energy as ATP. An analogy often used is that ATP is like a rechargeable battery.

Which gas is removed from the atmosphere during photosynthesis?

A. hydrogenB. oxygenC. nitrogenD. carbon dioxide

A weightlifter is using heavy weights in short bursts for a competition. Because his muscle cells are not able to take in enough oxygen to make very much ATP the weightlifter begins to get fatigue in his muscles. Which of the following processes is most likely going on in the muscles of the weightlifter as he competes in his event?

A. As the cells run out of oxygen they switch to anaerobic respiration, which allows the cell to make small amounts of ATP in the absence of oxygen.

B. As the cells run out of oxygen, they die off gradually and the weightlifter's muscles have fewer contracting muscle cells.

C. The cells will never run out of oxygen if the weightlifter is breathing.

D. As the cells run out of oxygen, they will continue to make the same amount of ATP, since oxygen is not required to make ATP.

What function does ATP carry out in living things?

A. aids in protein folding and coilingB. used to capture and transfer energyC. identifies DNA start sequences for

transcriptionD. helps maintain the fluidity of cell

membranes

How are cellular respiration and photosynthesis related, in terms of energy?

A. The energy captured in photosynthesis is used to power cellular respiration.

B. The energy transformed in cellular respiration is used to power photosynthesis.

C. Photosynthesis and respiration perform the same task in terms of energy transformation.

D. Energy is not involved in either photosynthesis or cellular respiration.

Two different species of bacteria are examined. Scientists find that species X always produces CO2 and H2O during cellular respiration. Species Y always produces ethyl alcohol and CO2. Which conclusion can be made from these observations?

A. Only species Y is aerobic.B. Only species Y is anaerobic.C. Both species X and Y are aerobic.D. Both species X and Y are anaerobic.

In which way are photosynthesis and cellular respiration different?

A. Cellular respiration stores ATP, while photosynthesis releases ATP.

B. Cellular respiration produces oxygen, while photosynthesis uses oxygen.

C. Photosynthesis releases energy, while cellular respiration stores energy.

D. Photosynthesis used carbon dioxide, while cellular respiration produces carbon dioxide.

The Krebs cycle, fermentation, electron transport, and the breakdown of starch are processes of respiration. Which process could take place within an airtight bottle that contained no oxygen?

A.Krebs cycleB.FermentationC.Electron transportD.Break down of starch