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Course: High school biology > Unit 3
Lesson 1: Introduction to metabolismIntroduction to metabolism review
Key Terms
| Term | Meaning |
|---|---|
| Metabolism | The sum of all chemical reactions that take place inside a cell |
| Anabolism | The synthesis of complex molecules from simpler ones |
| Catabolism | The breakdown of complex molecules into simpler ones |
| Exergonic reaction | A reaction that releases energy |
| Endergonic reaction | A reaction that consumes energy |
| ATP | Adenosine triphosphate, the primary energy carrier in living things |
Metabolism
Metabolism is a set of chemical reactions that interconnect in a series of pathways. It is a balancing act between the building and breakdown of molecules in the body.
| Type of metabolism | Process | Energetics | Example |
|---|---|---|---|
| Anabolism | Builds complex molecules from simple ones | Endergonic | Production of new body tissues |
| Catabolism | Breaks down complex molecules into simpler ones | Exergonic | Digestion of food |
Examples
Catabolism: Cellular respiration
Cellular respiration is a catabolic process during which glucose is broken down to release usable energy for a cell.
The overall reaction for cellular respiration is:
As in all catabolic processes, cellular respiration releases energy which can then be harnessed and used by other reactions in the cell.
Anabolism: Photosynthesis
Photosynthesis is an anabolic process during which plants use energy from sunlight to convert carbon dioxide gas and water into sugar molecules.
The overall reaction for photosynthesis is:
Photosynthesis, like all anabolic processes, consumes energy as glucose is built. Some of this glucose is used by the plant itself, or it can be used as a food source for other organisms.
Common mistakes and misconceptions
- Many metabolic reactions occur at the same time. Thousands of metabolic reactions are being carried out in your body at the same time. They are all coordinated with one another and regulated carefully to keep an organism functioning properly.
Want to join the conversation?
The more I know, I more I get confused with the concept of 'energy'. It seems to me that energy is very abstract, like an invisible force that pushes things around. So what exactly is energy?(28 votes)
Energy is what it takes to do work, mostly moving matter in the form of vibration/heat, rotation, and kinetic energy. Potential energy is the stored ability to do work. It is a name chosen for a specific unit.(20 votes)
I am a 11th grader and I am preparing to study medicine. Can anyone tell me if I have to know all the metabolic reactions such as glycolysis, glucogenesis... ?(13 votes)- Yes, you should know all of these metabolic reactions.(2 votes)
This is hard and confusing (probably because i am a 6th grader)(8 votes)
9th grade now, is it any easier?(7 votes)
How does Cellular respiration work?(6 votes)- hey mate, there are articles on cellular respiration in the next unit.(5 votes)
Why is photosynthesis an anabolic process and why is cellular respiration a catabolic process?(4 votes)
Anabolic processes are processes that build up compounds. That means higher energy bonds are created. Photosynthesis takes CO2 and H2O (quite low energy molecules), and then assembles them into glucose. Catabolism, which is the process of digestion and break down complex chemicals into simpler molecules.(4 votes)
- All of this is so confusing! can somebody please better explain?(1 vote)
- Metabolism is the process to either store or release energy, just like you live by spending money and saving it. Both are necessary. In our body, we're either building molecules or breaking them apart to give us what we need. Building molecules requires energy, which it gets from ATP. Building molecules is a process called anabolism: for a visual aid, just imagine your builder is called Anna. Taking molecules apart is catabolism: I imagine a cat coming in and breaking things down. Anna your builder needs energy to do her work of building molecules, so she takes what's called ATP. To remember ATP, just think "instead of an ATM that gives money, it's ATP." Anna the anabolic process cashes in her ATP money by converting it to a currency she likes more called ADP, which is done by tearing off a small part of her ATP bill. Cats (the catabolic), on the other hand, give money as an apology any time they destroy or break something apart. To be clear, no process is better than the other. So… just remember Anna the anabolic builder, cats the catabolic destroyer, and Anna who takes money and converts it to her currency (ATP to ADP) to build stuff, and cats giving money (energy/ATP) as an apology when they destroy stuff.(7 votes)
In the Metabolism section in this article, it shows a chart. Under Energetics it shows Endergonic and Exergonic. What do those mean?(4 votes)
Endergonic is a reaction that consumes energy and is involved in anabolism. Exergonic is a reaction that releases energy and is involved in catabolism.(0 votes)
- The more I know, I more I get confused with the concept of 'energy'. It seems to me that energy is very abstract, like an invisible force that pushes things around. So what exactly is energy?(3 votes)
Energy is what it takes to do work, mostly moving matter in the form of vibration/heat, rotation, and kinetic energy. Potential energy is the stored ability to do work. It is a name chosen for a specific unit.(2 votes)
- why are large molecules broke down into small molecules?(3 votes)
Your body mostly breaks them down to use for energy or other purposes or even rearranges them to make new and more useful molecules.(1 vote)
how do metabolic functions affect my everyday life?(3 votes)