Ok, so high school bio got me as far as the concept of animal cells and plants cells. Great. Putting that behind us, animal cells can then be broken down into smaller categories right? From what I can tell, they are at least broken down by species and function, but are there further categorical reductions to be made? Just as an example; red blood cells vs white blood cells (both human), how and why are they structurally different? Do their organelles differ in size, shape, number or composition? What about two red blood cells from the same person, are they structurally identical? Could all human red blood cell mitochondria be considered interchangeable? Identical? I know the cell nuclei can’t at least. I really want to stress structure here, not function. I know I just typed a lot of question marks, but I am not looking to have them all answered, just trying to convey the gist of what I am after. I think I am trying to understand the gap between the intracellular level and the atomic level.
PS. slightly unrelated; when ATP is hydrolyzed into ADP and phosphate; is the energy released by that reaction the same heat energy that our bodies radiate? Is the phosphate the same phosphate excreted in our urine? Seems like it to me but I cant find explicit confirmation.
In: Biology
Some good questions. A cell’s structure is going to be tied to what it does. Since there are a lot of cells with different functions in your body, there are a lot of differently structured cells of all different size.
For example, white blood cells are tasked with keeping your body safe from invaders. They have special components to them that a brain cell would not have, and brain cells have special components that white blood cells would not have.
So cells can have different organelles, be different sizes, have different structural components, and have different numbers of organelles/components inside of them. Some cells have multiple nuclei (certain muscle cells), some have one, and some have none (red blood cells). Also, you mentioned red blood cell mitochondria- RBCs don’t have mitochondria because they are tasked with carrying oxygen through the body, and mitochondria eat up oxygen to make energy.
To your other question: ATP hydrolysis does generate energy (or transfer energy, if we’re being precise in language). Simplistically, energy can be defined as either heat or work. Heat is what you think it is and work is when something does something. That thing could be pushing a box, forcing a sodium ion against it’s concentration gradient, or anything really. The energy used in ATP hydrolysis is coupled with a reaction to provide some extra energy. Note: nothing is 100% efficient, so when performing work, some energy will be lost as heat.
Please let me know if I’ve answered everything or if there’s anything you’d want me to clarify on
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