Biology
Ms. Tardalo
9/22/15
Name:______
Mitochondria and Chloroplasts
1)Mitochondria are responsible for the process we call cellular respiration.
- This process is carried out by every living organism.
2)Cellular respiration: the metabolic process that utilizes oxygen to convertthe energy stored in organic molecules (carbohydrates and lipids) to form ATP.
3)ATP stands for adenosine triphosphate, and is usable energy.
4)The chemical equation for cellular respiration looks like (label the reactants and products):
Reactants Products
5)Chloroplasts are responsible for the process of photosynthesis.
- This process is carried out by all organisms that contain chloroplasts.
- Most importantly, for our purposes, plants.
6)Photosynthesis :The process by which light energy is converted to chemical energy that is stored in sugars or other organic compounds.
7)The chemical equation for photosynthesis looks like (label the reactants and products):
Reactants Products
8)What do you notice about the two formulas?
The products of one reaction serve as the reactants for the other.
9)Mitochondria and Chloroplasts are very unique among all of the organelles. Some things that they have in common that set them apart are:
- Double membranes (they both have an inner and outer membrane)
- The both transform energy (change it from one form to another)
- They have their own ribosomes and make their own enzymes
- They have their own DNA (separate and different from that contained in the nucleus)
- The DNA is in the form of a plasmid, which is circular.
- They are free-moving (move around the cell) and self-replicating (divide and reproduce separately from the rest of the cell)
10)Because of these features, scientists think that, prior to becoming organelles, mitochondria and chloroplasts…..
Existed as their own, independent organisms
11)Endosymbiont Theory:
Symbiosis occurs when two different species benefit from living and working together. When one organism actually lives inside the other it's called endosymbiosis. The endosymbiotic theory describes how a large host cell and ingested bacteria could easily become dependent on one another for survival, resulting in a permanent relationship. Over millions of years of evolution, mitochondria and chloroplasts have become more specialized and today they cannot live outside the cell.
12)The Earth is approximately 4.5 billion years old.
13)Earth’s early atomosphere lacked oxygen.
14)Instead it consisted mostly of …..
Volcanic gases (methane sulfide and carbon dioxide)
15)The earliest known cells were prokaryotic (bacteria).
16)These prokaryotes did not need oxygen to survive.
17)anaerobes: organisms that do not need oxygen to survive
18)aerobes, organisms that require oxygen to survive, evolved much later.
19)This is because…..
There was little oxygen in the early atmosphere, and it wasn’t until photosynthetic organisms became prevalent, increasing the amount of oxygen enough so that aerobic organisms could come into existence.