Sweet, Sweet Succes(ful Regulation of Blood Glucose)

I hope you all have been good little boys and girls and grown man/woman-children, because as promised I am going to explain blood glucose regulation. Bad children are temporarily banned from learning. Don’t even try to keep reading. You don’t want to know the punishment.

Anyway, first of all, take a look at this cake:

LOOK AT IT.

 

We shall be considering this masterpiece of sweet, sweet heaven (courtesy of Stephanie Michaelis at Raspberri Cupcakes) for the rest of my post. Additionally, we have two scenarios: eat the cake and gaze longingly at photos of/not eating the cake.

Now, let’s imagine we get to eat some of this colorful, culinary delight. After some digestion, the pancreas recognizes the resulting increase in blood glucose. The pancreas has exocrine (secretes chemicals such as alkaline solution and digestive enzymes via ducts) and endocrine (secretes hormones directly into the bloodstream) tissues. Within the endocrine tissues are beta cells, the most abundant endocrine cell in the mammalian pancreas. Beta cells synthesize and secrete insulin in response to increased blood glucose. Insulin then travels to the liver and signals glycogenesis; the production of glycogen in skeletal muscle as well as the liver. Insulin will also inhibit gluconeogenesis (the production of glucose from molecules such as pyruvate or lactate) and facilitate glucose transport to cells. As a result, blood glucose will decrease to normal levels.

OK, back to reality. We do not get to eat the cake. We get to salivate with intense longing at the computer screen. We lose track of time. We forget to make a sandwich for lunch. Blood glucose drops. The pancreas detects this drop and other cells in its endocrine tissue, the alpha cells, produce and secrete glucagon into the bloodstream. Because the glucose…is GONE. Get it? Get it? Anyway, the liver receives this signal, glycogen production then decreases while glycogenolysis (glycogen break-down) increases along with gluconeogenesis. Blood glucose then increase to a more normal level.

Insulin and glucagon do not act exclusively of one another, with every spike and drop in blood glucose they work together to bring things back to normal. Of course, they can’t act instantly and can only go so far. For instance, Insulin would struggle if you inhaled an ENTIRE cake, while I can personally advise against long fasts if you want to do anything requiring focus like say…navigating Chicago by yourself on your first visit without passing out on the sidewalk on the way to the taxi. Those are bad life choices; spiking your blood glucose too high too often has long-term consequences and passing out on the sidewalk in a strange city has ALL the consequences.

So be street smart, carry snacks.

 

Source

Sherwood, Lauralee, Hillar Klandorf and Paul Yancey. 2005. Animal Physiology: From Genes to Organisms. Thomson Brookes/Cole, Belmont, CA.

 

Photo credit:

Michaelis, Stephanie. 2011. “Purple Ombre Sprinkles Cake.” Raspberri Cupcakes. 19 November, 2013 <http://www.raspberricupcakes.com/2011/11/purple-ombre-sprinkle-cake.html&gt;

Hard Core-al

So sorry for the prolonged bouts of silence, guys. I’m just finishing up an online stats class and I’ve had a quiz, a final project and a final to work on/prepare for. The madness will end soon, but until then my posts will be a little sparse. Now onto more fun things.

Coral is fun, right? Right. They are colonial polyps of the phylum Cnidaria, and what’s more fun than saying “polyp”? NOTHING. Possibly cake. But anyway! As cnidarians, coral are related to jellyfish and anemones, and like anemones, they possess nematocysts (stinging cells) on their tentacles for filter feeding. Unlike anemones, they maintain a symbiotic relationship with algae, they help out with stuff like cooking, cleaning, provide energy through photosynthesis, etc. You know, symbiont stuff. However environmental stressors (like ocean acidification) can cause the coral to eject the algae, a process called bleaching (for the color change that accompanies the algae eviction) from which the coral do not usually recover. Barring changes in/removal of temporary stressors. For those of you crazy chemistry people, my marine bio professor has been researching the protective, anti-bleaching role of organic osmolytes (imagine a chemical cushion against change) in coral. You can check some of it out here and here.

Although coral colonies have a wide variety of shapes, species follow one of three strategies: columnar, planar and massive. Columnar coral grow tall, fast, in order to stay in the sun and avoid getting shaded out. Planar coral would be the ones doing the shading; they don’t grow tall, but they grow wide and flat (like the one in my picture) to prevent other coral from growing around them. The wide plates of these coral are also great for absorbing sunlight. Finally, there are the massive coral. These grow slowly, it may take hundreds of years for one to actually qualify as “massive” and in the meantime, they have competitors ready and willing (or at least as willing as a coral can be) to destroy them. However, massive coral have a secret weapon, massive coral have war tentacles. Excuse me, WAR TENTACLES. WAR TENTACLES are TENTACLES used in WAR. Territorial coral of any species just stretch out their stingy tentacles and go at it, massive coral are just better at it and have evolved to possess TENTACLES particularly suited to WAR. It’s a slow war, but give them a break. They’re coral.

 

Sources

Yancey, Paul. “Coral Reefs.” Marine Biology. Whitman College. Walla Walla, WA. 5 4 2011. Lecture.

Picture credit: me.

Best of Buds

No, it is not my birthday, this is my cake from a birthday long (less than two years) past. Now, I am not a lady usually tempted by fancy cheesecake concoctions. Not really a lady in the first place. But if I saw pina colada or mint choco-brownie or raspberry-mocha-berry-fudgestravaganza cheesecake on a menu I’d typically reply with a scowl and a violent crossing of arms. So it is shocking I even considered hot buttered rum cheesecake. But consider it I did. Besides devouring and digesting it. This was not some weak cheesecake with delusions grandeur of being a dessert drink, this was hot buttered rum reincarnated as a cheesecake for good deeds in its previous life. It was glorious.

My supreme enjoyment was all thanks to gustation. We all should thank our sense of taste; life would be a lot paler without the many tastes of our body fuel. Out would go birthday cake, fanciful cocktails, wine tasting and Cheezits. Spinach with bleu cheese salads, chocolate and mango juice would all be gone with the wind. We would just eat bizarre mashes of what’s good for us and enthusiastically tolerate it all. So then thank GOD AND ALL THAT IS HOLY for taste buds.

You have about 9000 taste buds and despite all the hype about them being color-coordinated taste microphones, they are a bit more complex than that. But just a bit. Taste buds are not the little nubbins all over your tongue, but the taste cells bordering the nubbins are the ones that really work the gustatory magic. The buds are composed of receptor cells and supporting cells. Receptor cells are modified epithelial (inner skin) cells that possess many folds to allow as much taste juice onto them as possible. This “tasting site” is the taste pore. Molecules and ions in the macerated food bind to the pore and results in a chain reaction: the receptor cells provoke an action potential (Remember action potentials?) in connecting nerve fibers and the brain in eventually alerted to the presence of tastiness (or not).

So what triggers this response? Well, it depends. Humans can taste sweet, salty, sour, bitter and meaty things and each have different ways to excite your senses. I will address this is detail tomorrow, but for now I will add that spicy is not a taste. It is your taste buds crying for a ceasefire.

Source

Sherwood, Lauralee, Hillar Klandorf and Paul Yancey. 2005. Animal Physiology: From Genes to Organisms. Thomson Brookes/Cole, Belmont, CA.

Photo credit me. Cheesecake credit, Kensie Steakhouse.