This is similar to what I know about DNA and how the DNA Polymerase moves from 5' to 3', similar to how motor proteins move from the + to - (or vice versa) end of microtubules. #lightbulb-moment

Are lysosomes the only cell in the endomembrane system that can do phagocytosis?

Does the fact that peroxisomes have single membranes help with their function within the human body?

Are all cases of double membranes a case of endosymbiosis, or are there some exceptions?

Is secondary active transport similar to diffusion since they both rely on gradients to facilitate their movement? #just-curious

I know passive transport typically only occurs with small and nonpolar molecules. Is this pattern the rule for transport within cells or are there important exceptions to remember?

Both are using the idea of going from high to low concentration. However, passive diffusion can happen without the help of a protein while facilitated needs one.

Is it safe to say then for any interaction, one system will always be exothermic and the other will be endothermic (ex. air/environment would be exothermic, plan system endothermic)? **assuming energy is exchanged?

I want to refute the statement: take tumors for example. The biological definition is a clump of cells that cause tumors. Some are deadly while some are not, this in itself is already a disordered state where there isn't a set outcome for one event. And the way a tumor builds is because there is some flaw in the cell making process and is causing an extremely disordered state that there is suddenly a lot more cells in the human body than they are used to.

This is like the conservation of mass law in chemistry, aka the reason why equations must be balances (same amount of elements in the reactants and products).

I learned a similar concept in physics when learning about the difference between heat and thermal energy. Heat is an energy transfer, which means its the method in which thermal energy is moved within a system or out of a system.

I think that to better understand dieting, I would need to know the averse-affects of too much lipids and carbohydrates. I agree that complete removal of carbs is not a healthy nor sustainable diet, but limiting carbs and fats could be beneficial depending on the person.

Aren't all lipids amphipathic because they have a polar head and nonpolar tail?

In my previous bio class, I learned that cholesterol is in the plasma membrane so reinforce the structural integrity if the membrane is too "liquid-y". But also provides somewhat of a block in between phospholipids so the plasma membrane doesn't clump/freeze up.

Butter has more structure at a warmer temperature, therefore I would assume it does not have a kink, which I presume would mess with the structural integrity/stability of a molecule.

Most, if not all of these lipids have polar heads comprised of carboxylic groups and the rest of the bodies are just carbon chains. Is it possible to have a lipid with elements other than carbon, oxygen and hydrogen?

I know this is only a wording problem, but I don’t understand what high affinity oxygen means? For example, my guess would be that high affinity (being drawn to something) would mean a higher % saturation?

From previous biology classes, we mainly learned about pH in terms of denaturing proteins/structures. Are there any other instances in biology where pH is relevant?

When a molecule is deprotonated/protonated, is it always with a hydrogen atom? Or it doesn’t matter as long as a proton is being added/removed?