What two characteristics of a membrane structure influences membrane fluidity?

I think temperature is one since saturated fats are present but what could the other one be?

Its asking about structure.
1) length of carbon tail. Longer= less fluid
2) # of double bond/kinks in the carbon chain. More= more fluid as they can pack as tightly

Oh thanks, I think the question just confused me the way it was worded, thank you.

I also have one other question:A dietary supplement is developed that makes NAD+ less efficient at binding electrons. Would this supplement be used for weight loss or weight gain? Explain the effects this supplement would have on cellular respiration to support your choice.

This question is worth 5 points so I need a good response and I honestly don't have a clue...this is a test redo that I'm doing and on the original test I said it would be weight gain because the faster your metabolism, the easier you lose weight and since it doesn't bind electrons as well then your metabolism would slow down because less chemical reactions are taking place. I got docked 4 out 5 points so obviously I didn't know what I was talking about even though I thought I did :/.