Metabolism

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Metabolism

• Jessica F. and The Rayman

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Basic Terms

• Anabolism
• Anabolism is the process by which a cell
  combines smaller molecules into larger, more
  complex molecules. Such as carbohydrates, lipids
  and proteins. By doing this, a cell can store
  energy in the molecules and use it later.
• Anabolism is most commonly used build up organs
  and tissues in an organism.
• Catabolism
• Catabolism is the opposite of anabolism. It
  refers to the process by which large polymeric
  molecules that were formed by anabolism are
  broken down into their less complex forms (such
  as amino acids and monosaccharides
  respectively).
• The main way that anabolic and catabolic
  reactions take place is hydrolysis and
  dehydration reactions.

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Hydrolysis and DehydrationReactions
To the right is an example of a
dehydration reaction. It shows water being taken
out of sucrose to build a larger molecule out of
two smaller ones. This is an anabolic process and
stores energy in the large molecule when it is
formed. Also, it shows a hydrolysis
reaction. It is just the opposite of a
dehydration reaction. By adding water to the
large polysaccharide, you end up splitting the
molecule in two. This produces energy.

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Just what and where is Metabolism?

• Metabolism refers to the total sum of all the
  anabolic and catabolic processes that happen
  within a cell or organism. The anabolic and
  catabolic process are performed through a series
  of complex chemical reactions known as metabolic
  pathways. The metabolic pathways are catalyzed by
  various enzymes. There are a few different types
  of these enzymes, and they all do different
  things

Classic catabolic hormones Cortisol

Glucagon Adrenalin(e)
and other catechizations Cytokines
Classic anabolic hormones Growth hormone IGF1
and other insulin-like growth factors Insulin
Testosterone Oestrogen
Due to the fact that it is
counterproductive to have anabolic and catabolic
processes occurring in cells simultaneously,
there are many signals that switch on anabolic
processes while switching off catabolic processes
and vice versa.
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Lots of Energy

• Energy is the ability to do work
• Potential energy is stored in the chemical bonds
  of molecules. Carbon-carbon and carbon-hydrogen
  bonds are relatively rich in energy. This energy
  is released when the chemical bond is broken. The
  released energy will be metabolized in a form
  that can be easily used by the cell.
• Kinetic energy is the energy an object has
  because it is in motion like moving, crying or
  eating.
• Work is the transfer of energy from one place to
  another.
• Bond energy is the minimum energy required to
  break one mol of bonds between two species of
  atoms.

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Lots and lots of Energy

• Adenosine triphospahte (ATP) is the key source of
  free energy (energy that can do useful work) in
  living cells.
• When the cell requires free energy to drive an
  endothermic reaction, an enzyme called ATPase
  catalyzes the hydrolysis of the terminal
  phosphate of an ATP molecule, resulting in a
  molecule of ADP, a molecule of inorganic
  phosphate and the release of 31KJ/mol of FREE
  ENERGY.

ATP H2O ? ADP Pi ?G -31
KJ/mol
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Do some MATH now
Type of activity Energy Factor (KJ/kg/h)
Sleeping 4.1
Cooking 10.5
Bowling 13.6
Climbing stairs 37.5
Competitive cross -country skiing 73.6
Sleeping for 8 hours Energy factor (KJ/kg/h) X
body mass (kg) X time (h) 4.1 (KJ/kg/h) X 75 kg X
8h 2460 KJ (to convert pounds to kg your
weight in pounds / 2.2)
Energy requirement Teenage girl 9500
KJ/day Teenage boy 12000 KJ/day
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Fun Facts

• People getting gt 9200 KJ/ day are considered
  starving.
• Larger people have greater cells and greater
  energy needs.
• The more active a person is the greater their
  energy requirements are.
• Different people, even if they have same body
  mass, have different rate which metabolism occurs
  in body.
• A chemical messenger produced in the thyroid
  gland regulates the rate at which food energy is
  converted into other forms of energy by the cells
  of the body.
• If the release of the chemical messenger from the
  thyroid gland increases metabolism increases.
• A person with a high metabolic rate converts a
  larger portion of the food energy into heat, less
  food energy is converted into fat and the person
  remains relatively thinner.

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Energy