Biochem Lipids, Membrane Structure And Transport

Front 1

Why are dietary essential fatty acids important?

Back 1

1) can influence fluidity of membrane
2) can pass BBB
3) deficiency can lead to scaly dermititis, hair loss, poor wound healing

Front 2

What affects the melting point of fatty acids?

Back 2

INCREASES w/ chain length
DECREASES with degree of unsat. (double bonds)

Front 3

What does fatty acid synthesis in humans lead to mainly?

Back 3

palmitate (16:0)

Front 4

What is the structure of linoleic acid?

Back 4

18:2 (omega 6)

Front 5

What is the structure of arachidonic acid?

Back 5

20:4 (omega 6)

Front 6

What is the structure of alpha-linoleic acid?

Back 6

9:12 omega 3, important for brain

Front 7

If humans cannot change a fatty acid to a different omega family, how do we derive nutrients from EFAs?

Back 7

A smaller member of the same family can be used to form a larger fatty acid. (i.e. DHA 22:6 from alpha linolenic) omega 3 fam

Front 8

Structure/function of TAGs?

Back 8

unpolar, main storage form of fatty acids. stored in adipocytes

Front 9

Distinguish difference between phospholipids and glycolipids.

Back 9

both amphiphatic. phospholipids have glyercol backbone. glycolipids: sphingolipids with sugars attached to ceramide

Front 10

Composition/function of phosphatidycholine?

Back 10

-syntehsizes sphingomyeline
-provides lung surfactant (dipalmitoyl-PC)

Front 11

Composition/function of phosphatidylethanolamine

Back 11

component of membrane lipids

Front 12

Composition/function of plasmalogens

Back 12

analogues of heart and nerve tissue, contain ether linkage in pos 1

Front 13

Composition/function of phosphatidylserine

Back 13

negative charge overall

Front 14

Composition/function of phosphatidylinositol

Back 14

is cleaved to DAG and IP3 by phospholipase C in Ca 2nd messenger syndrome. 20:4 omega 6 in opsition 2

Front 15

Composition/function of cardiolipin

Back 15

found in inner mitochondrial spaces, 4 fatty acids 18:2 omega 6. deficiency leads to Barth's syndrome

Front 16

Composition/function of sphingomyelin

Back 16

found in plasma membranes. important for myelin of nerve fibers & grey matter.

Front 17

Composition/function of cerebrosides

Back 17

found in brain, PNS, and myelin sheaths.
-ceramide + sugar= cerebrosides

Front 18

Composition/function of globosides

Back 18

found in brain, PNS, and myelin sheath.
-cerebrosides+sugar= globosides

Front 19

Composition/function of gangliosides

Back 19

found at nerve endings, formed when NANA is linked to globosides.

Front 20

Discuss lung surfactant in Respiratory distress Syndrome

Back 20

-deficiency leads to RDS.
-also found in adults whose lung surfactant cells have been damaged.
-lung maturity predicted by lecithin/sphingomyelin ratio. 2 or above related to maturity

Front 21

Structure and importance of cholesterol?

Back 21

unpolar, amphipathic.
Steroid hormone synthesis needs cholesterol in:
-Adrenal cortex (cortisol, aldosterone)
-Ovaries
-Testes

Front 22

What is the fluid mosaic model for membrane structure?

Back 22

-phospholipid bilayer and embedded proteins which allow easy lateral movement

Front 23

What is the complex lipid composition of plasma membrane?

Back 23

-contains integral, peripheral, lipid-anchored proteins
-outside a glycocalyx (layer of glycolipids and glycoproteins)
-shield, cell-cell recognition

Front 24

Factors regulating membrane fluidity?

Back 24

-cholesterol inside of bilayer increases
-cholesterol close to polar heads decreases
-shorter fAs/unsat. FAs increase fluidity

Front 25

Function of cholesterol in plasma membrane?

Back 25

-increase/decrease fluidity
-stabilizes by increasing fluidity @ low temp, decreasing fluidity @ high temp

Front 26

Differentiate btwn active and passive transport

Back 26

passive-doesn't require ATP, relies on permeability of cell membrane
active-ATP, vs. concen grad.

Front 27

Discuss facilitate diffusion.

Back 27

-compound can flow into cell when concen grad. allows
-specific, saturable (can measure Tmax and Kt)

Front 28

Distinguish between primary and secondary active transport.

Back 28

-Primary-Na/K ATPase
Secondary- concentration grad. of Na by primary active transp.
-cotransport w/ Na

Front 29

Explain role of ABC transporters (ATP Binding Casette)

Back 29

-gated Cl- opens after phosphorylation by protein kinase A
-Cl- will diffuse into EC space
-CFTR channel

Front 30

How do defects in membrane transport lead to cystic fibrosis?

Back 30

-Defect of CFTR
-sweat cells, ion flow is reverse and re-uptake of Cl- and H2O is defective
-salty sweat on forehead

Front 31

Which method of facilitated transport of glucose is insulin-dependent?

Back 31

GLUT-4
-patients w/ diabetes can't use efficiently

Front 32

Which method of facilitated transport of glucose transports mainly fructose but glucose @ high concentrations?

Back 32

GLUT-5
-found in IMC and testes

Front 33

Which method of facilitated transport of glucose has a large Kf and very efficient at high glucose concentrations?

Back 33

GLUT-2
-found in IMC, liver, kidney, pancreas

Front 34

Which method of facilitated transport of glucose is are abundant in RBC and brain?

Back 34

GLUT-1

Front 35

Which method of facilitated transport of glucose is dominant of neurons?

Back 35

GLUT-3

Front 36

What is SGLT's role in secondary active transport?

Back 36

performs secondary active transport, transports 1 glucose and 2 Na ions into cell