8.1 How Organisms Obtain Energy

Transformation of energy
Energy is the ability to do work
Thermaldynamics the study of the flow and transformation inthe universe

Law of Thermodynamics
-First law Energy can be converted from one form to another,but it cannot be creatednor destroyed
-Second law energy cannot be converted without the loss of usable energy (heat,friction,sound,light,etc)

Autotrophs and Heterotrophs
Autotrophs organisms that make their own food .Ex)plants,some protist(algae),and some bacteria.
Heterotrophs organisms that need to ingest food to obtain energyEx)animals,fungi, some protist (amoeba,paramecia,and some bactreia

Metabolism all of the chemical reactions in a cell

Photosynthesis light energy from the sun in converted to chemical energy (glucose)for use by the cell

Celluar Respiration organic molecules (glucose)are broken down to release energy for use by the cell

Glucose C6 H12 O6 CH2O

ATP-the Unit of Celluar Energy
-ATP the energy currency of all the cells
-ATP-stored and releases a small amount $1 of energy for movement,transport and other active processes in the cell
-Both herterothrophs and autotrophs use ATP as an energy storage molecule in their cells.
-ATP is used to power processes in the cell such as the Calvin Cycle of photosynthesis in which CO2 is converted into glucose.


-ATP used for movement within the cell.
-produced during cell respiration when carbohydrates such as glucose are broken down.
Energy is released when the third phosphate on ATP is removed and transferred to another molecule.
this leaves behind ADP(adenosine diphosphate).



8.2 photosyntesis
Photosynthesis process by which the energy of the sun is used to convert H2O and CO2 into high energy sugars (glucose)
Importance we need glucose and other carbohydrates for energy but we cannot produce themselves.We also need oxygen and this is produced during photosynthesis plants and algea.

Light Energy
-light is form of energy that travels in the form of PARTICLES or WAVES.The waves are measured in wavelenths , which vary in length.Humans can see violet through red wavelenghts (REMEMBER ROY G BIV)
Color reflected light .We see color
Pigment a molecule that absorbs light.
Whatever colors the pigment does NOT absorb are what we see.



Pigments
cholorphyll a
is pigment that ABSORBS violet,red,and blue wavelengths of light.
Green is REFLECTED by chlorophyll a.That's why most leaves appear green to us.
Other pigments called ACCESSORY PIGMENTS (chlororphyll b,xanophll,and carotene ) help chlorophyll a absorb a absorb a greater spectrumof light.

Chloroplasts
Photosyntesis takes place in the chloroplast.
Chloroplast: Double-membrane, disk - shaped organelle
located inside this disk are stacks of sacks.

Each sack is called a thylakoid
inside each thylakoid is chlorophyll and other pigments.
Stacks of sacks are called grana.
Surrouding the grana is a fluid called stroma


The Calvin Cycle
light INDEPENDENT reactions
GOAL:uses the ATPand NADPH from the light reaction to convert CO2 into carbohhdrate (glucose)
WHAT GOES IN:ATP,NADPH,CO2,RuBP(a sugar)

WHAT COMES OUT:Glucose (stored by the plant)ADP,P,NADP+:(shuttle back to the light reactions light charged up again)

Step 1: Six CO2 molecules combine with six RuBP to form twelve 3-carbon molecules called 3-PGA
Step 2;ATP provides energy and NADPH provides H+ to transform the 3-PGA molecules into twelve high-energy molecules called G3P.is essentially a half glucose
Step 2: continued : TWO G3P (half-glucoses) leave the cycle to become glucose
Step 3:An enzyme called rubisco converts the remaining ten G3P molecules back into 6 molecules of RuBP
Step 4:The 6 RuBP COMBINE WITH 6 NEW co2 TO CONTINUE THE CYC

Alternative Pathways- the H2O/CO2 problems
C4 plants

-Adaptation to conserve water in hot regions.
-instead of 3-Carbon stages (3-PGA and G3P ), these plants fix
-Able to keep stomata closed on hot days and Calvin Cycle occurs in special cells
-Used by sugar cane and corn.

-Conserves water in dry regions .
-Only open stomata for CO2 at night.
-Holds the CO2 until daytime .Calvin Cycle proceeds while stomata are closed.

8.3 Cellular
Overall Goal: To completely break down glucose and transfer the energy to ATP
Location : jn the cytoplasm and mitochondria of all eukaryotic cells.
C6H12O6+6O2--->6CO2+6CH2O=ENERGY

Cellular respiration occurs in two main parts.
Glycolysis
Aerobaic resipiration

Glycolysis
Glucose is broken down in the cytoplasm through the process of glycolysis

Two molecules of ATP and two molecules of NADH are formed for each molecule of glucose that is broken down.

Location :cytoplasm GOAL: to break glucose ($100) into 2 pyruvates ($50).Does not require Oxygen therefore it is ANAEROBIC
WHAT GOES IN: Glucose + 2 ATP'S (''INVESTED)
WHAT COMES OUT: 2 PYRUVATES ($50)
2 ATP's ($1) (NET)
2 NADH's ($10)
9 step process with 2 phases:
energy consuming /investing
energy releasing

Glucose enters the cell by facilitated diffusion
2 ATP's PHOSPHORYLATE glucose which make it more reactive
Glucose breaks down into two 3-Carbon molecules

-Used by pineapple and cacti.