Fat is to fuel like protien is to ...........

Having a coffee shop discussion this morning and we were comparing the human body to a gasoline engine. We all agreed that the we both have to breath air, and that fuel is like fat or calories for energy and that water keeps us hydrated and cooled. Oil is kind of like blood, electrical was like nerves and brain etc. where we didn’t agree with was protein or muscle and some disagreement on the skeleton. I felt muscle was the actual ignition of the fuel or the expanded gasses and that the metal engine case was skeletal. I was surprised how many viewed the housing as muscle and skeleton combined and the actual burning of the fuel the same as fuel.


was this in a coffee shop in Amsterdam?

Its not a perfect analogy since cars generally don’t grow or repair themselves, but I would say that protein is like the metal that makes up the car.

Or solder, or glue.

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Yes. Except it’s a car that can burn metal, at least in part, when it needs to. :wink:

The problem with using analogies is that they often aren’t really that analogous. Yeah, you can make a “fat:body::fuel:car” analogy, and it’s reasonable enough if you keep it at that, but it doesn’t work as an extended metaphor. Cars don’t run on gas (carbohydrates) that they reform into pitch (lipids) that they store under their fenders in case they run out of gas, and they aren’t made of millions of tiny cells (cells) that are built out of pitch. Likewise, wires (neurons) aren’t made out of pitch. I could keep going because there are billions of ways that cars are different from bodies and only a handful of ways in which they’re similar, mostly in that they both take in chemical energy and turn it into heat and motion.

If you really need an analogy to explain how proteins works, I guess the body is like a chemical plant made out of rubber? Petroleum distillate (proteins) is used as a raw material for all sorts of products, both reactive and structural, and helps form the scaffolding of the whole thing. Vitamins are minor reagents and catalysts that don’t come from the petroleum, and uh, I guess carbohydrates and lipids are electricity? It’s not a really good analogy because we aren’t chemical plants made out of rubber. :{}

Probably a closer analogy would be that the entire engine is just the muscle behind any thing you might attach it to.

I agree that this is where the analogy starts to break down, since the car doesn’t build itself. Likewise, blood is a weak analogy for oil, since oil doesn’t carry the air and fuel to the cylinders.

So the closest we can do is that bone is the frame (for non-unibody cars – do they still make cars with frames?) and protein is the rest of the metal and plastic and whatever.

Some of these are getting pretty crude, though, lol. For example, oil is used for cooling and lubrication. Blood carries oxygen and nutrients, while removing waste. Blood is more like the intake, exhaust, and fuel injection systems.

Skeleton would be the cars chassis, parts of the suspension, powertrain, etc.

Muscle wouldn’t just be a “part”, IMO. It would also be the torque created by the motor, all parts which interact with the crankshaft which are involved with converting chemical energy to mechanical, and associated components on down to the wheels, depending on the type of car (including flywheel and gearbox).

PSXer’s answer is funny, though.:slight_smile:

I would say that fat = fuel is a bit incomplete; say instead that the car is a hybrid and that fat represents electricity from the big, honkin’ battery, the energy you use for all the basic tasks and the basic grunt work of powering the car. Glucose would be the equivalent of fuel (gasoline), the stuff you use for sudden bursts of power or speed.

Wouldn’t that make the battery the liver? Then the stored electricity would be glycogen :slight_smile:

Fuel/gas is to ATP.

As oil is to synovial fluid.

As windshield wipers are to eyelids.

The horn is the larynx.

The glove box is either the vagina (A place to stash drugs), or the anus. (Full of crap.)

Licence plate and VIN are the fingerprints.

The onboard computer and sensors are a homeostatic control system.

The driver is the brain.

The seat cushioning is like lipids supporting organs.

The reversing camera is an eye.

The airbag is like a penis - mostly floppy and limp, mostly only of any use when inflated.

The indicators and brake lights are like the face - people can make assumptions about what you are going to do in the next few seconds based on what signals your face is outputting.

Now, protein…that is hard. I’ll go along with the plastic/glue/long chain hydrocarbons analogy.

Are we talking protein, or muscles? For muscles, I think it would be whatever it is in a car that coverts energy into movement or stopping of movement. So the crankshaft and wheels and steering wheel and brakes, maybe? I know very little about the mechanics of cars.

Protein makes up muscles, but it does so much else, it’s really hard to make a one-to-one correlation there. Amino acids are literally the building blocks of everything, and the instructions for how to make everything. Proteins are hormones (messengers, so carwise, all those little warning lights and gauges, maybe) and proteins make channels in our cells to move things in and out (doors?) and proteins make skin, nails and hair (rustproofing and paint?) and proteins work in our immune systems (hmmmm…antifreeze, maybe? That protects cars from the ill-effects of cold…that’s a stretch…)

Proteins are, literally, everything and everywhere. And I’m not just saying that because I’m here posting while I procrastinate creating my PowerPoint on amino acids and proteins for Biochemistry… :smiley: