So, I’m designing an alien race, called the ___________. They live on planet ________. My question is, what type of biology could make creature get effects similar to alcohol, but with sugar?
Your species are type 1 diabetics.
People with type 1 diabetes do not make insulin. Ingested sugar causes an uncontrolled rise in blood sugar. This can lead to diabetic ketoacidosis. Many of the symptoms of DKA overlap with those of alcohol intoxication. Police pulling over an impaired driver can have difficulty telling the two apart.
Drivers who are suffering from a diabetic incident and have an excess of ketones in their system, also known as ketosis, may appear to be under the influence of alcohol. Drivers experiencing ketosis will often emit a sweet smell on their breath that police officers may confuse with alcohol. These drivers also may appear to be sluggish, confused and lackadaisical, which may be confused for alcohol or drug impairment. These drivers will be asked to complete various field sobriety tests and may have problems with coordination or balance as a result of ketosis or diabetic ketoacidosis. As a result, the driver may be arrested on suspicion of driving under the influence of alcohol as a result of the “physical indicia of intoxication” observed by the investigating officer.
In addition to the cognitive / psychologic effects (sleepy / aggressive / silly etc) people with DKA also get plain ill, which you seem to be looking for (throwing up, passing out etc).
Maybe your species evolved in a circumstance where there were barely any carbohydrate foodstuffs and so they did not need insulin. Maybe in their new circumstances they all developed type 1 diabetes.
For a story, a problem with DKA is that in humans with type 1 diabetes DKA can kill and so if you are going to play drunkenness for laughs that does not seem right. But you can riff off of the DKA idea and give the aliens some failsafe insulin-like hormone - some sort of inefficient substance that begrudgingly and slowly cleans up the mess after the sugared-up aliens stagger around in DKA for a while; sort of like alcohol dehydrogenase does for us. Animals like horses with loads of alcohol dehydrogenase are immune to getting drunk. As regards alcohol we are to horses what your aliens are to us as regards sugar.
Thinking a little further, you could hand wave your alien DKA such that the serious dehydration and electrolyte abnormalities only happen with the worst cases, but that excess production of acetone happens a lot. DKA is a mix of being sick and intoxicated, and the acetone is responsible for a lot of the intoxication - symptoms from acetone excess are similar to those of ethanol excess. So you sugar drunk aliens would reek of nail polish remover and otherwise just act drunk.
Well, as pojo-guy pointed out, this actually can happen with an excess of yeast in the body and a relative dearth of the enyzyme responsible for breaking down alcohol (alcohol dehydrogenase). It would also theoretically be possible if the enzymes—blanking on their names at the minute—responsible for breaking down the two other poisons that alcohol dehydrogenase converts alcohol into were missing, and a body couldn't make the jump to the terminal glucose-water mixture.
That said, if you just mean "intoxicated" in an alcohol-like way, there are a lot of other ways to do it. Alcohol technically refers to any chemical that contains a hydroxyl bound to carbon; and most of them aren't digestible at all by humans, but have a similar (and potentially lethal) toxicology and definitively a similar chemistry.
I don't like the idea of depending on yeast to form an alcohol, when we're obviously dealing with another planet; so let's look at the chemistry of fermentation. Assuming we're talking about sucrose sugar, the first thing yeast does is cleave it into fructose and glucose. Once that's done, the glucose is broken down into pyruvate and a phosphate; the pyruvate molecule then gets a hydrogen ion tacked onto it and the enzyme pyruvate decarboxylase takes a whack at it, and you end up with ethanol, and a whole bunch of other crap.
The issue is, this is relatively one-way; your organism would likely still need a symbiotic relationship with another organism that does this in order to produce the alcohol. In turning glucose into alcohol, and alcohol back into glucose, you would get zero chemical energy gain. Many of the effects of drunkenness are also derived from our attempt to metabolize it. Sugar is a simple and relatively harmless carbohydrate. So I would say, have your microbial symbiote (like mitochondria for mammals) digest the sugar and produce alcohol in a manner similar to how yeast does, and the host deal with the alcohol enzymes.
Your aliens are Ruminants. Then you can do the whole alcohol making process in house.
For sugars to ferment you need to have a couple of things: sugar, a solvent (usually water) and yeast. Temperature influences the speed of the fermentation. The solvent is needed for the yeast to be able to work. Plain sugar (or honey) and yeast will not ferment.
So yea, when a ruminant, like a deer, eats sugars and yeast they can get drunk on it. Apples will do so.