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Overview of Metabolism

Metabolism is a system of chemical reactions in which the organism will obtain energy, reducing power and carbon compounds from their environment and utilize it to carry out life processes and make biological molecules.

In other words, its consists of the break down, degradation, (catabolism) and the building of molecules, biosynthesis, (anabolism).

There’s a lot we can say about metabolism, but we can save that for Biochemistry. I don’t think we need that information for this class, right now.

  • Just remember that Catabolism breaks stuff down, and Anabolism just builds everything up.
  • Knocking something down would be so much easier than building something up, think of a brick building!
  • Another note is the measure of energy is in kilo Calories, think of when you are burning calories (exercising) you’re sweating, hence, you’re releasing heat (a form of energy).

How are the cells in our body able to break down and build macromolecules in our body?

ENERGY!

  • are seen in many different forms, in science its usually termed as heat
  • in Chemistry, breaking the bond between two chemical compounds will give you energy since it took lots of energy to even build those bonds in the first place (refresh that chem, hopefully I’ll get that up here soon)
  • In metabolism, we will see a great energy contributor, ATP! (you know, the compound found in mitochondria) and it contributes by breaking away its third and high energy bond.

Is made from ADP + inorganic phosphate through variety of chemical processes in the cell. An abudance of it is made in the electron transport cycle.

What is ATP made up of?

As you can see, ATP (adenosine triphosphate) contains an adenosine (amino group, an amino group because it has an amine), a ribose sugar (the one with the OH and O), and three phosphates. Hence, its name! It too, is a major building block for DNA.

What’s the difference between the metabolism in Cold and Warm blooded animals?

Cold Blooded – reptiles, fish, insects, (endotherms)

  • dependent on environment because if it is too cold, the metabolism will slow down, and remember metabolism is both catabolism and anabolism, so if this is poor; you’ll get poor digestion and poor synthesis (both of which are extremely important in your well being)

Warm Blooded – birds, mammals (exotherm)

  • are independent of the environment’s temperature because they have a specific metabolic rate (of course, it may slow down as you age, but that is more physiology than microbiology right now, another subject to discuss later)

NUTRITION

In order for metabolism to even occur, we need to be fed. In all organisms there are some sort of energy source. A diagram will soon follow, but for now, we’ve got to major energy sources: chemical and light. Organisms using oxidation reduction reactions in catabolism or anabolism are called chemotrophs. Organisms using light for catabolism or anabolism are called phototrophs. Both chemotrophs and phototrophs utilize carbon sources.

Basically, heterotrophs are ones that utilize organic compounds (carbons that are attached to hydrogens ie. CH2). In contrary autotrophs are ones that utilize inorganic compounds (carbons that are NOT attached to hydrogens ie. CO2)

Some are called chemoheterotrophs, chemoautotrophs, photoheterotrophs, and photoautotrophs.

Can you guess what each means before looking it up?

WHERE DO WE GET THE ENERGY AND MAKE THE NEEDED CONSTITUENTS IN GLUCOSE METABOLISM?

In Aerobic Respiration or Aerobic Metabolic Mechanism:

  1. GLYCOLYSIS
  2. KREBS CYCLE
  3. ELECTRON TRANSPORT CHAIN

In Anaerobic Respiration or Anaerobic Metabolic Mechanism:

  1. Denitrification
  2. Sulfate reduction
  3. Methanogens

Other Glucose Metabolism

  1. Fermentation

WHAT OTHER TYPES OF CATBOLISMS ARE THERE BESIDES THE BREAKDOWN OF GLUCOSE?

  1. Carbohydrates Catabolism
  2. Lipid Catabolism
  3. Protein Catabolism

PHOTOTROPHS METABOLISM

  1. Photosynthesis

Metabolism is a very dense topic and must be described in multiple posts. Hopefully this one gave you a general idea how things work. I will post every type of metabolism listed in in later posts.

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