cellular respiration
the energy in a chemical bond can be visualized as
potential energy contained in the electrons that make up the bond. Cells harvest this energy by putting the electrons to work, often to produce ATP. afterwards the energy-depleted electron is donated to some other molecule.
Exergonic reaction
releases energy
Cellular respiration is
the primary way that chemical energy is obtained from food and converted into ATP. An aerobic process; it requires oxygen. (glucose and oxygen food is broken down into ATP)
why do metabolic pathways yield energy (ATP)
because movement of electrons are transferred and relocated during chemical reactions. This releases energy (ATP).
In order for cellular respiration to occur
starts with monomers
ATP synthase
takes the energy from this flow, synthesizes ATP
Stage 2. Formation of Acetyl Coenzyme A (occurs in mitochondria)
Pyruvic acid loses a carbon; the carbon departs as carbon dioxide. the remaining 2 carbon molecule is an acetyl group which combines with a cofactor called coenzyme A forming acetyl coenzyme A, NAD+ is converted NADH
photosynthesis
plants convert light energy from the sun into chemical energy through photosynthesis
autotrophs are --- because ecosystems depend upon them for food
producers
Glycolysis uses
two ATP molecules per glucose to split the six-carbon glucose.makes four additional ATP directly when enzymes transfer phosphate groups fuel molecules ADP
cellular respirtation can generate
up to 38 molecules of ATP per molecule of glucose
Stage 2: Formation of Acetyl Coenzyme
NAD picks up 2 electrons to NADH peeled off to electron transport chain later on.
Citric acid cycle
extracts the energy of sugar by breaking the acetic acid molecules all the way down to CO2, Uses some of this energy to make ATP, forms NADH, & FADH2
The oxidized molecule
gives up energy (LEO)
a common fuel molecule for cellular respiration is
glucose
Other organic molecules either convertered to
glucose or enter the pathways of glucose metabolism
Later in cellular respiration at the end of the pathway there is an electron transport chain which
involves a series of redox reactions, ultimately leads to the production of large amounts of ATP
Catabolism
is the breakdown of large, complex molecules into simpler compounds, often with a release of energy.
Glucose metabolism is
less complex than the metabolism of other organic molecules
Cells cannot extract energy from
macromolecules; they must be broken down into monomers (hydrolysis). This process occurs through the action of enzymes
All single celled organisms and every cell of multicellular organisms can
metabolize glucose
oxygen dependent
process by which organisms break down organic molecules and extract energy from food molecules. (food molecules break down in the form of ATP)
the reduced molecule
receives energy (GER)
Every oxidation reaction is accompanied by a
reduction reaction, Reactions of this type is called oxidation reduction reactions or redox reactions
ATP also has to be
regenerated from ADP and inorganic phosphate.
Stage 4: Electron Transport
releases the energy your cells need to make most their ATP, electron transport chain passes electrons to oxygen via many energy releasing steps, water is produced as byproduct, most of the ATP that is generated in cellular respiration is produced by the electron transport chain***
Glycolysis
"splitting of sugar"
Stage 1: Glycolysis
a six carbon glucose molecule is split in half to form two molecules of pyruvic acid. These two molecules then donate high energy electrons to NAD+ forming NADH
Glycolysis produces
a net two molecules of ATP per glucose molecule
the molecules of the electron transport chain
are built into the inner membranes of mitochondria, the chain functions as a chemical machine that uses energy released by the "fall" of electrons to pump hydrogen ions across the inner mitochondrial membrane, these ions store potential energy
Enzymes break large molecules into smaller one in the
digestion process. Other enzymes can break down these small molecules. ( Carbs, lipids, fats, proteins are foods we eat which use energy. 1st mechanical digestion hits your stomach you have the enzymes breaking bonds making molecules smaller)
what is the energy currency of the cell
ATP
All reactions involved in cellular resp. can be grouped into four stages
Glycolysis, formation of acetyl coenzyme A, the citric acid cycle, electron transport
cellular respiration is
a controlled fall of electrons, a stepwise cascade much like going down a staircase
Most eukarytoic cells and many prokaryotic cells are
aerobic, they require oxygen.
Cellular respiration is
an exergonic reaction. It releases energy available to do work.
Many prokaryotes and a few eukaryotes can live
anaerobically, without oxygen Ex: prom-bacteria, euk-yeast.
energy flow and chemical cycling
animals depend on plants to convert solar energy to the chemical energy of sugars and other food molecules we consume.( metabolic pathways sugars can be produced in proteins)
Animals perform only
cellular respiration
both heterotrophs and autotrophs obtain energy by breaking down organic molecules in a process called
cellular respiration
oxidation reduction reactions are part of
cellular respiration and photosynthesis, As electrons pass from one atom to another they carry energy with them. (hydrogen atoms are simple 1 proton 1 electron, h+ loss electron can see this in cellular respiration or just the electron)
The role of oxygen in cellular respiration
cellular respiration can produce up to 38 ATP molecules for each glucose material consumed.
Cellular respiration and breathing are related
cellular respiration requires a cell to exchange gases with its surroundings, cells take in oxygen gas, cells release waste carbon dioxide gas, breathing exchanges these same gases between the blood and outside air. (product of cellular respiration)
plant and animal cells perform
cellular respiration, a chemical process that primarily occurs in mitochondria, harvests energy stored in organic molecules, uses oxygen, generates ATP
energy is contained in
chemical bonds
The reactions of cellular resp. and photosynthesis are
complementary
Stage 3: The Citric Acid Cycle
completes the breakdown of sugar, also known as krebs cycle, reactions occur in matrix of mitochondria. ( Entry point is 2 carbon combines with 4 carbon molecule, conversion with organic compounds keep arranging it by products carbon dioxide load more electrons in co enzymes NADH and FADH2)
hetertrophs are --- because they eat plants or other animals
consumers
In addition to glucose cellular respiration can "burn"
diverse types of carbohydrates, fats, proteins, these organic molecules enter the aerobic cellular respiration pathway at different points.
cell use ATP for activities that require work. ATP is also used to drive
endergonic reactions
During cellular respiration
hydrogen and its bonding electrons change partners, hydrogen and its electrons go from sugar to oxygen forming water, this hydrogen transfer is why oxygen is so vital to cellular resp. during cell. resp. glucose is oxidized and oxygen is reduced.
Acetyl Co-A
important because many metabolic processes generate it.( break down fats produces entry point to the citric acid cyle, what happens to it depends on how much ATP is in a cell)
heterotrophs(other feeders)
include humans and other animals, fungi and most protists that cannot make organic molecules from inorganic ones.( protists green algae)
Plants and other autotrophs (self feeders)
make their own organic matter from inorganic nutrients, includes plants, and most algae and bacteria, not all of them photosynthesize
ATP occurs in the
mitochondria and is generated in it.
Extracting energy
occurs in stages
Cellular respiration is an example
of a metabolic pathway which is a series of chemical reactions in cells
When an atom or molecule loses an electron is is
oxidized and the process is called oxidation (LEO)
Both breathing and cellular respiration take in
oxygen and release carbon dioxide
When an atom or molecule gains and electron it is
reduced and the process is called reduction.(GER)
Glycolysis begins with
the addition of energy (ATP) there is a net gain oe 2 ATP (invests energy to get started)
Cellular respiration refers to
the biochemical pathways that extract energy ATP from the bonds of nutrient molecules in the presence of oxygen. (respiration gas exchange)
When hydrogen ions flow back through the membrane, they release energy
the hydrogen ions flow through ATP synthase.
Digestion occurs in
the intestinal tract of animals.small molecules can then move across the cell membrane into the cell.
How do organisms supply themselves with energy?
the major energy transformations are cellular respiration and photosynthesis, ultimate source of energy for most organisms is sunlight.
NADH and electron transport chain
the path that electrons take one their way down from glucose to oxygen involves many steps. each step is catalyzed by an enzyme
*there is a chemical cycling between photosynthesis and cellular respirtation
the reactants of photosynthesis are carbon dioxide and water. Carbon dioxide is obtained from the air by the plants leaves and water is obtained from the soil by the plants roots. The waste product of cellular respiration are carbon dioxide and water which are used in photosynthesis. Photosynthesis produces sugars and other organic molecules as well as oxygen which is used in cellular respiration. * the reactants of one are the products of the other.
In glycolysis the first step in the cellular respiration process there is an electron acceptor called NAD+
the transfer of electrons from organic fuel to NAD+ reduces it to NADH
Some organisms are facultative anaerobes
they use oxygen when it is available, but can live without oxygen.
why does electron transfer to oxygen release energy
when electrons move from glucose to oxygen it is as though the electrons were falling. This "fall" of electrons releases energy during cellular respiration.( control cascade of electrons which you max energy gain)
Important coenzyme energy carriers include
NAD(myosin as its base),FAD(flaming adenine),and the cytochromes. ( They shuttle electrons and hydrogens in step in cell.resp.)
In glycolysis this stage glucose
a 6 carbon molecule is split into 2-3 carbon sugar molecules, pyruvic acid, This process occurs in the cytoplasm and involves a sequence of 10 reactions each catalyzed by an enzyme. This stage does not require oxygen and proceeds the same way under aerobic and anaerobic conditions.
Oxidation almost always involves
the removal of a hydrogen atom and reduction a gain in hydrogen atoms
plants perform
photosynthesis and cellular respiration
Cellular work converts
ATP to ADP and inorganic phosphate.
