Biochemistry: Lipids and Membrane Stucture and Transport
Quiz yourself by thinking what should be in
each of the black spaces below before clicking
on it to display the answer.
Help!
|
|
||||
|---|---|---|---|---|---|
| What are the different functions of Lipids? | Storage of fat (TAGs), energy metabolism, thermal insulator, plasma membrane, vitamins A,D,K,E, steroid hormones
🗑
|
||||
| Describe the structure and properties of fatty acids. | Long hydrocarbon tail with charged carboxyl, amphipathic, MP increases with chain length and decreases with degree of unsaturation, free fatty acids are esterified
🗑
|
||||
| Describe fatty acids in humans | in humans 16-20 carbons & double bonds cis @ 3-interval carbons. Can only be desaturated between carbons 9/10 or between 9/10 and carboxyl end
🗑
|
||||
| Synthesis of fatty acids usually leads to: | palmitate
🗑
|
||||
| What are the essential fatty acids? | linoleic acid and alpha linolenic acid
🗑
|
||||
| Can humans change a fatty acid of a high family to a lower? | no but a smaller member of the same family can be used to form a larger fatty acid
🗑
|
||||
| What is linoleic acid essential for and what happens during its deficiency? | Synthesis of arachidonic acid. Deficiency leads to mead acid (marker for EFA deficiency)
🗑
|
||||
| What is the intravenous method to administer EFA? | total parenteral nutrition
🗑
|
||||
| What is the clinical relevance of TAGs? | Main form of storage of fatty acids. Can be stored in adipocytes which only increase/decrease in size in non-obese ppl
🗑
|
||||
| Which phospholipids contain a different backbone other than glycerol? | spingomyelin-contains a sphingosine backbone
🗑
|
||||
| Describe glycolipids | Spingolipids with sugars attached to ceramide
🗑
|
||||
| Describe the synthesis of ceramide | palmitoyl-CoA and serine (plus vitB) produces ceramide
🗑
|
||||
| What is ceramide a component of? | spingomyelin, cerebrosides, globosides and gangliosides
🗑
|
||||
| What is the function of ceramide in skin? | regulates the water permeability of skin
🗑
|
||||
| What is the importance of sphingomyelin? | found in outer leaflet of PMs and important for myelin of nerve fibers & grey matter.
🗑
|
||||
| What is the biological importance of glycosphingolipids and sphingomyelin? | defective degradation leads to lysosomal storage disease
🗑
|
||||
| Describe the synthesis of cerebrosides and globosides. | Ceramide+sugar=cerebroside +sugars=globoside
🗑
|
||||
| Describe the synthesis of gangliosides | N-acetyl-neuraminic acid+globoside
🗑
|
||||
| What is the biological importance of cerebrosides, globosides and gangliosides? | cerebro and globo found in brain and peripheral nervous tissue and myelin, gangliosides in ganglion cells of CNS
🗑
|
||||
| Describe the structure of glycerophospholipids. | phosphatidic acid. 1 fatty acid is saturated, 2 fatty acid unsaturated
🗑
|
||||
| Biological importance of phospatidylcholine | major component of membrane lipids. Analogue of plasmalogen in heart.
🗑
|
||||
| Biological importance of phospatidylethanolamine | major component of membrane lipids. Analogue of plasmalogen in nerve tissue.
🗑
|
||||
| Which glcerophospholipid is not a major membrane lipid? | phosphatidylserine
🗑
|
||||
| Biological importance of phospatidylinositol | Used to form PIP2 which is cleave by phospholipase C to DAG and IP3 in Ca2+ second messenger system.
🗑
|
||||
| Where is cardolipin found? | inner mito membrane
🗑
|
||||
| Biological importance of cardiolipin | Deficiency leads to Barth's syndrome a rare but severe cardiomyopathy.
🗑
|
||||
| Biological importance of phospatidylcholine | Major membrane component. Released in bile. Used for sphingomyelin synthesis. Provides dipalmitoyl-PC for lung surfactant.
🗑
|
||||
| How is phoshpotidylcholine made? | from choline or phosphotidylethanolamine methylation
🗑
|
||||
| How can you predict lung maturity in infants? | the lecithin (phosphotidylcholine)/sphingomyelin ratio must be 2 or above
🗑
|
||||
| What are all the functions of cholesterol in the body? | unpolar-storage/transport in lipoproteins, regulation of PM fluidity, steroid hormone synthesis, vitD synthesis, liver bile acid synthesis
🗑
|
||||
| What steroid hormones are formed by cholesterol? | adrenal cortex:cortisol, aldosterone, androgens. ovaries:estradiol. testes:testosterone
🗑
|
||||
| What is the precursor of cholesterol used for vit D deficiency? | 7-dehydrocholesterol
🗑
|
||||
| What are the functions of biological membranes? | separate cell from external environment, allow specific reactions to be localized
🗑
|
||||
| What is the glycocalyx composed of and what is its function? | glycolipids and glycoproteins. acts as a shield and involved in cell-cell recognition
🗑
|
||||
| Describe the functions of cholesterol inside the lipid bilayer. | increases fluidity inside bilayer while sterol rings decrease fluidity close to polar heads. Can increase/decrease fluidity with temp change.
🗑
|
||||
| How do fatty acids affect membrane fluidity? | unsaturated and shorter fatty acids make membrane more fluid
🗑
|
||||
| Examples of unsaturated fatty acids in membranes? | oleic acid, linoleic acid and arachiodonic acid
🗑
|
||||
| What types of molecules can penetrate the lipid bilayer? | gases, hydrophobic molecules and small polar molecules.
🗑
|
||||
| What cannot pass the membrane? | charged and large polar molecules
🗑
|
||||
| What kind of transport is required for glucose inside of a cell? | passive facilitated diffusion.
🗑
|
||||
| What does a high Kt signify? | low affinity of transporter to substrate.
🗑
|
||||
| Describe the transporter of glucose | 12 TM domains. , (low Kt for both). , liver, kidney and beta-cells of pancreas
🗑
|
||||
| Where is GLUT-1 found? | GLUT-1 (low Kt) in RBC and brain
🗑
|
||||
| Where is GLUT-2 found? | GLUT-2 (high Kt) intestinal mucosal cell (enterohepatic circulation), liver, kidney and beta-cells of pancreas
🗑
|
||||
| Where is GLUT-3 found? | GLUT-3 (low Kt) in neurons
🗑
|
||||
| Where is GLUT-4 found? | insulin-dependent-fat cells and muscle (low Kt)
🗑
|
||||
| Where is GLUT-5 found? | (high Kt) intestinal mucosal cell (intestinal lumen) and testes. (mainly frutose transport, glucose at high concentration)
🗑
|
||||
| What is the biological relevance of GLUT-4? | patients with diabetes can't use GLUT-4 efficiently. It is stored inside the cell.
🗑
|
||||
| Describe the SGLT transporter. | secondary active symporter. pumps glucose into intestinal mucosal cells with 2 Na ions
🗑
|
||||
| Describe the CFTR channel | ABC-transporter. Phosphorylation gated (PKA). Two ATPs cleaved and channel opens for chloride ions and Na exits via paracellular tight junctions. Water follows
🗑
|
||||
| What happens to males with CF? | congenital bilateral absence of vas deferens
🗑
|
||||
| Describe the mutation leading to CF | codon deletion of phenylalanine causing CFTR to not be transported to the membrane
🗑
|
||||
| What affect does cholera have on CFTR? | leads to an unregulated CFTR
🗑
|
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:
mnoronha
Popular Biochemistry sets