What are Singer and Nicolson known for?
One-gene-one-enzyme hypothesis
Plasma membrane modifications
Fluid-mosaic model of plasma membrane
Structure of DNA
In a 50 gm living tissue, what would be the amount of water
15- 25 gm
25 - 30 gm
35- 45 gm
70- 90 gm
The outermost limiting layer of mycoplasma is made up of
cell wall
cell membrane
mucilaginous sheath
slime layer
Specific proteins responsible for the flow of materials and information into the cell are called
membrane receptors
carrier proteins
integral proteins
none of these
B.
carrier proteins
Active transport is the uphill movement of materials across the membrane where the solute particles move against their concentration gradient or electro- chemical gradient. It takes place through special organic molecules called carrier molecules or carrier particles or carrier proteins. For each solute particle, there is a special carrier molecule. It has its own binding site on the two surfaces of the membrane. Substrate combines with the carrier to form carrier solute complex. It further undergoes a conformational changes and is transported to other side of the membrane. ATP provides energy to the carrier.
Assertion : Nucleus is the controlling centre of a cell.
Reason : Pores in the nuclear envelop regulate the flow of materials in and out of the nucleus.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false
Which of the following is responsible for the mechanical support, protein synthesis and enzyme transport?
Cell membrane
Mitochondria
Dictyosome
Endoplasmic reticulum
In prokaryotes, chromatophores are
specialized granules responsible for colouration of cells
structures responsbile for organizing the shape of the organism
inclusion bodies lying free inside the cells for canying out various metabolic activities
internal membrane systems that may become extensive and complex in photosynthetic bacteria
Many cells function properly and divide mitotically even though they do not have
plasma membrane
cytoskeleton
mitochondria
plastids