A level Biology Chapter 6 - Digestion+Absorption
Help!
|
|
||||
|---|---|---|---|---|---|
| Explain why maltse catalyses only this reaction? (maltase > maltose hydrolysed) | specific tertiary structure of enzyme = specific active site shape complementary to specific substrate of maltose only. Every enzyme specific shape = only makes enzyme substrate complex with specific active site and substrate
🗑
|
||||
| What organ produces maltase? | Small Intestine
🗑
|
||||
| Name one other digestive enzyme located in the plasma membrane of cells lining the small intestine? | Dipeptidase
🗑
|
||||
| Give an advantage of lactase and other digestive enzymes being located in the plasma membrane of cells lining the small intestine rather than being secreted by lumen of SI? | enzymes not lost with gut contents. More effective absorption of products by these enzymes
🗑
|
||||
| Absorption of galactose from SI is reduced if absorbing cells are treated with respiratory inhibitor. Suggest an explanation for this? | No ATP made.
Therefore less galactose moves into cells by active transport.
🗑
|
||||
| Describe role of Rough ER in formation of chylomicrons? | For protein synthesis, chylomicrons are made of proteins
🗑
|
||||
| How do chylomicrons leave the epithelial cell? | Exocytosis because chylomicrons are very large.
🗑
|
||||
| Describe the role of enzymes of the digestive system in the complete breakdown of starch? [5 marks] | Salivary amylase hydrolyses starch into dissacharide maltose. Maltase breaks down maltose to glucose by hydrolysing glycosidic bonds
🗑
|
||||
| Describe the processes involved in the absorption of the products of starch digestion? | Glucose moves in with sodium via carrier protein,
sodium removed from epithelial cell by active transport (sodium potassium pump) into blood.
🗑
|
||||
| Why does damage to the microvilli mean people will have a lower conc of aa in their blood | Less surface area, less absorption takes place. damage to channel proteins amino acids wont be absorbed as fast,
🗑
|
||||
| Why does higher conc of bile salts (smaller droplets of bile salts) cause a mixture of bile salts and lipase to become a lower PH | smaller droplets = larger SA = larger surface for lipase to act so more triglycerides digested. More fatty acids produced which lowers PH.
🗑
|
||||
| How are epithelial cells of SI adapted for the absorption of glucose? [6 marks] | Microvilli- Increase SA so diffusion can happen at a faster rate.
Thin - Short diffusion pathway
Many carrier proteins for active transport.
Many mitochondria for ATP
channel/ carrier proteins for facilitated diffusion
Membrane bound dissacharidases
🗑
|
||||
| Describe the action of these membrane bound dipeptidases and explain their importance? | Break the peptide bonds and absorb amino acids.
🗑
|
Review the information in the table. When you are ready to quiz yourself you can hide individual columns or the entire table. Then you can click on the empty cells to reveal the answer. Try to recall what will be displayed before clicking the empty cell.
To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Created by:
ksatti12