producers
organisms that can use energy ffrom the sun to produce food through photosynthesis (plants on land, and phytoplankton in water)
consumers
organisms that obtain their energy by eating plants (herbivores eat directly, carnivores, indirectly by eating other animals that have eaten plants)
photosynthesis
- using energy from sunlight (carbon dioxide from the air and hydrogen from water)
- glucose (C6H12O6) is made
- oxygen is released as a “waste” product
cellular respiration
- glucose is broken down using oxygen
- energy in glucose is converted to energy carried by ATP (energy to do work in the cell)
- carbon dioxide and water are released as waste products
cycle or circle of life
- consists of photosynthesis and cellular respiration
- plants need oxygen and carbon dioxide and we provide that becase that is what we breathe out or have as waste products
- vice versa we need oxygen, and that is what plants release
the human body uses ___
-atp for almost all of its activities
Life sustaining activities use as much as ___
75% of the energy a person takes in as food a day (heart beat breathing, maintaining body temperature, digesting food etc)
efficiency of cellular respiration
- car engines are only able to convert about 35% of the potential energy in gasoline into kinetic energy to move the car (most of the rest is heat)
- similarly, cellular respiration is able to harvest about 34% of the potential energy in glucose and store it in ATP (most of the rest is heat)
how breathing is related to cellular respiration
-when we inhale, we breathe in oxygen
-oxygen is delivered to cells where it is used by cellular respiration
-carbon dioxide, a waste product of cellular respiration, diffuses from your cells to your blood and travels to your lungs where is is exhaled
-
steps of cellular respiration
- glycolysis
- citric acid cycle (krebs cycle)
- electron transport chain
* goal = generate as much ATP as possible
glycolysis
- glycol (glucose), lysis (to break)
- takes place in the cytoplasm
- glucose (6C) is broken in half into two molecules of pyruvic acid (3C)
- high energy hydrogen electrons are carried to Electron Transport Chain (ETC)
- some ATP is generated (2 ATP)
citric acid cycle
- pyruvic acid (3C) moves into mitochondria
- a complicated cycle where the sugar is broken down completely (C-H bonds broken; carbons are removed releasing carbon dioxide which is why we breath out carbon dioxide)
- some ATP generated (2 ATP)
- higher energy hydrogen electrons are carried to ETC
electron transport chain
- ETC
- high energy hydrogen electrons are dropped off and they move through ETC
- this is where most of the ATP is generated
- oxygen is at the bottom of the ETC, pulling the electrons through the chain
- thus, oxygen powers the ETC, generating ATP (and also some water)
- electrons give up some of their energy by pumping H+ across the membrane through electron carriers
- H+ can only flow back across the membrane through ATP Synthase
- as H+ flows through ATP Synthase, the energy is used to generate ATP
- produces about 28 ATP
ATP Synthase
an enzyme that generates ATP
total ATP formed from one molecule of glucose
about 32 ATPs
each ATP contains about ___ of the then ___
- ?%
- energy in one molecule of glucose
rotenone
to kill insects and fish (blocks electron transport
cyanide and carbon monoxide
block electron transport (which stops ATP production, can kill you)
DNP
-leaks H+ across membranes, banned weightloss drug
people would lose weight without doing anything
-dangerous because not releasing any heat
olygomycin
- blocks ATP Synthase
- used against fungi
fermentation
- an anaerobic alternative to aerobic respiration
- yeasts, some bacteria, and our muscle cells can break down sugar without using oxygen
- small amount of ATP generated (2ATP per molecule of glucose)
anaerobic
without oxygen
aerobic
with oxygen (cellular respiration)
types of fermentation
- lactic acid
2. alcoholic fermentation
