Lipids as pigments in plants and bird feathers.

Birds acquire the pigments that color their feathers red or yellow by eating plant materials that contain carotenoid pigments, such as canthaxanthin and zeaxanthin.

The differences in pigmentation between male and female birds are the result of differences in intestinal uptake and processing of carotenoids.

TLS Online TPP Program

#Id: 8132

#XL - Q Biochemistry

Lipids as pigments in plants and bird feathers.

Birds acquire the pigments that color their feathers red or yellow by eating plant materials that contain carotenoid pigments, such as canthaxanthin and zeaxanthin.

The differences in pigmentation between male and female birds are the result of differences in intestinal uptake and processing of carotenoids.

TLS Online TPP Program

#Id: 8132

#XL - T Zoology

Lipids as pigments in plants and bird feathers.

Birds acquire the pigments that color their feathers red or yellow by eating plant materials that contain carotenoid pigments, such as canthaxanthin and zeaxanthin.

The differences in pigmentation between male and female birds are the result of differences in intestinal uptake and processing of carotenoids.

TLS Online TPP Program

#Id: 10065

#XL - T Zoology

Two type of Cadherins:

1. Classical cadherin proteins

2. Nonclassical cadherin proteins

TLS Online TPP Program

#Id: 10066

#XL - T Zoology

Extracellular region of a classical cadherin contains five copies of the cadherin domain separated by flexible hinge regions

TLS Online TPP Program

#Id: 10067

#XL - T Zoology

Ca2+ ions bind to sites near each hinge and prevent it

from flexing, so that the whole string of cadherin domains behaves as a rigid and slightly curved rod to generate cell–cell adhesion

TLS Online TPP Program

#Id: 10069

#XL - T Zoology

Each classical cadherin molecule contains: 

A single TM domain

A short C-terminal cytosolic domain

Five extracellular “cadherin” domains (EC1–EC5)

TLS Online TPP Program

#Id: 10070

#XL - T Zoology

Three classes of classical cadherins: 

E-cadherin -present on epithelial cells

N-cadherin - present on nerve, muscle and lens cells

P-cadherin - present on cells in the placenta & epidermis

TLS Online TPP Program

#Id: 10071

#XL - T Zoology

Nonclassical cadherins include proteins:

Protocadherins found in the brain

Desmocollins and desmogleins that form desmosomes