Answer:
B (active transport using ATP)
Explanation:
Movement of substances normally occur in the direction of concentration gradient/difference i.e. the difference in concentration of a substance across a membrane. Letting molecules diffuse or pass down their concentration gradient does not require energy but pumping those molecules against gradient requires energy in form of Adenosine triphosphate (ATP). This process is called Active transport.
In order to perform certain cellular processes, cells need to move substances from their surroundings into the cell across their cell membrane. Moving this substances against the concentration gradient between the cell membrane and its extracellular fluid requires energy (ATP).
An example is the sodium-pottasium pump employed by animal cells in which they expend energy to move K+ molecules into the cell and Na+ molecules outside the cell against the concentration gradient of their cell membrane and extracellular solution.
Its D) UGCUGC because this sequence is the mrna if it was the dna sequence it'd be B but its definetly D
The kind that messes everything up I guess
Answer:
Explanation:
The four elements been referred to here are hydrogen, oxygen, carbon and nitrogen.
These four elements constitute the majority of the human body because of a combination of factors. Although, some of these factors are the major reasons, for instance the human body is made up of cells which are the basic structures of life. The cell consists of over 70% of water (which is made of hydrogen and oxygen). Also, oxygen is inhaled through the process of respiration which combines with other molecules (such as haemoglobin to form oxyhaemoglobin) in the human body. These among others make oxygen the most abundant element in the human body.
Naturally occurring organisms usually have a high concentration of organic molecules (molecules made of majorly carbon and hydrogen). This makes the human body have a high percentage (after oxygen) of carbon and hydrogen. Also, carbohydrates (which are later converted to glucose) form a large part of our diet and are stored in the body as glycogen (causing the body to have a high amount of carbon and hydrogen atoms).
Nitrogen is an essential part/element found in amino acids which are building blocks of protein. Proteins are involved in several metabolic activities in the body; this makes the abundance of nitrogen the fourth (one of the four) most common element in the body. It should be noted that amino acids also have carbon and hydrogen elements also.
The combination of the factors above among some other factors make the human body comprise mainly of these four elements
Cyclin-dependent kinases (Cdks), along with cyclins, are major control switches at these checkpoints. They are central to cell cycle control; their activation via cyclin mediates progression through all four phases of the cell cycle. p53 is a protein that functions to block the cell cycle if the DNA is damaged
