Which substance makes up most of the environment inside a cell?

Explain why people are searching ways to use biofuels made from plants to power cars

Tanzania [10]

Because people use too much gas and oil. If they made plant biofuel people wouldn't spend a lot of money and we wouldn't waste oil.

3 0

3 years ago

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The nurse is planning care for a patient going to surgery. who is responsible for informing the patient about the surgery and po

Goryan [66]

The doctor is responsible for all of the above.

5 0

4 years ago

What are the two principle forms of ossification that occur in the development of the skeletal system

In-s [12.5K]

<h2>Answer:</h2>

<em>Ossification is a process in which the mesenchymal cells and cartilages convert to bone during development. it is has two types: Membranous and endochondral ossifications. It occurs in mesenchyme which has formed a membranous sheath (figure 4) .</em>

4 0

3 years ago

For this assignment you will complete an illustration(s) (by hand) of how the lac operon works. You should be sure to include de

Fantom [35]

<h2>Lac operon </h2>

Explanation:

Lac operon present in prokaryotic chromosomes whose product involves in transportation and catabolism of lactose

Lac operon consists of three structural genes called Lac Z,Lac Y and Lac A and a regulatory element(promoter and operator)
Lac I gene is present outside the Lac operon,act as regulatory gene and control the expression of Lac operon genes
Lac Z codes for β galactosidase which converts lactose into allolactose
Lac Y codes for Lac permease which act as a membrane transporter and transport lactose into the cells
Lac A codes for transacetylase which neutralize the toxic effects of lactose

Lac operon in absence of lactose

In absence of lactose Lac operon exists in switch off state
Lac I gene produces Lac repressor which binds to operator region and prevent binding of RNA Polymerase thus blocks transcription

Lac operon in presence of lactose

In presence of lactose Lac operon exists in switch on state
In presence of lactose few molecules of Lac operon enzyme catalyse conversion of lactose to allolactose
Allolactose act as an inducer,binds to the Lac repressor and induce conformational changes causing dissociation of Lac repressor from operator
In absence of Lac repressor RNA Polymerase binds to the promoter and starts transcription of genes which catabolize lactose

Lac promoter is a weak promoter and direct transcription of Lac operon genes in very low level in presence of lactose

For higher level expression of Lac operon genes,operon system require conversion of weak promoter to strong promoter which is always mediated by catabolite protein-cAMP complex(CAP-cAMP complex)
CAP cAMP complex binds to the upstream of promoter called CAP binding site and stimulate expression of Lac operon genes by facilitating binding of RNA Polymerase
Catabolite activator protein(CAP) or cAMP receptor protein(CRP) activate when cAMP binds
cAMP is a secondary messenger synthesized from ATP and act as co-activator of CRP
With respect to CAP cAMP complex Lac operon system is positively controlled
In prokaryotic cell cAMP is very low when glucose concentration is relatively high and vice versa
At high concentration of glucose the growth rate is maximum and lactose catabolism is repressed called catabolite repression

6 0

3 years ago

Help please!! will mark brainliest

Anna11 [10]

Answer is the first option Place a metal paper clip on a table and slowly bring each electromagnet closer to the paper clip to see which can attract the paper clip from a greater distance.

I don't know why but I find your questions a bit too easy..

7 0

3 years ago