Biochemistry week 13 Flashcards
What is the chemical formula of Carbohydrates
Cn(H2O)n
What are carbohydrates composed of
Monasacharide building blocks
Name the 4 types of Carbohydrates
- Monosaccharides
-Disaccharides
-Oligosaccharides
-Polysaccharides
What are oilgomonasacchardies made of
- 3-10 monosaccharides
What are polysaccharides made of
- Long chains of monosaccharides conected by glycosisidc bonds
Name 3 monosaccharides
- Glucose
-Galactose
-Frcutose
Name 2 disaccharides
-Sucrose
-Lactose
Name 3 polysaccharies
- Cellulose,starch,glycogen
What do simple carbohydrates consists of
-Monosaccharides and disaccharides
What does comples carbohydrates consists of
- Polysaccharides
What are Aldoses
- Carbohydrates with an aldehyde group as the most oxidized functional group.
What are Ketoses
-Carbohydrates with a ketone group as the most oxidized functional group.
What is the first step of Carbohydrate digestion(Digestion of Polysaccharides and Disaccharides)
- ## Breaking down the polymers into simpler soluble form
Where does digestion of carbohydrates start
- In the mouth .
Where the saliva has a slighly acidic pH of 6.8 and contains salivary amylase
What is the overview name of the 2nd step of carbohydrate metabolism
- Conversion to monosaccharides
Explain how the Di + polysaccharides are converted to Monosaccharides
+ examples of enzymes
- Enzymes in the intestine break down the di + polysaccharides to monosaccharides by intestinal saccharides.
Maltases: Hydrolyze di- and trisaccharides.
Specific Disaccharidases:
Sucrase-isomaltase: Breaks sucrose and isomaltose.
Lactase (β-galactosidase): Breaks lactose.
Trehalase: Breaks trehalose.
What is the final step of digestion of carbohydrates
- They are absorbed in the intestine via
-Passive diffusion
-Facilitated diffusion
-Active transport
What is the name of the 2 intestinal transportors for glucose uptake
-Sodium Dependent (SGLT1)
-Sodium independent (GLUT2)
Explain the sodium-depenedent (SGLT1) transporter for glucose
Sodium-Dependent (SGLT1):
Primary transporter for glucose and galactose from the small intestine.
Uses sodium (Na⁺) gradient for active transport
Explain the sodium independent (GLUT2) transporter for glucose uptake
- Transports glucose into intestinal cells during glucose-mediated translocation
- Plays a role in glucose uptake into the portal circulation
How is fructose absorbed in the intestine
Via GLUT5, which is a specialised transported with a high affinity for fructose
What is the mechanism of SGLT1( sodium dependent) for the absorption of Na:
-The role of Na gradient
-Maintaining the Na gradient (pump)
- Role of Na⁺ Gradient:
The intestinal lumen has a higher Na⁺ concentration compared to epithelial cells, enabling Na⁺-dependent glucose transport.
Maintaining the Na⁺ Gradient:
A Na⁺, K⁺-ATPase pump on the basolateral membrane actively removes Na⁺ from epithelial cells into the extracellular space, preserving the Na⁺ gradient.
Glucose Absorption:
After uptake via SGLT1, glucose is transported into the bloodstream.
What is the function of GLUT transporters
Facilitate passive diffusion of glucose and fructose from areas of higher to lower concentration.
Explain the model for transport and how GLUT glucose transportes work
Binds glucose on one side of the membrane, undergo a conformational change , and then release it on the other side of the membrane
