Hey there friend!
Electrons come from atoms.
Hope this helps!
Answer:
The correct answer will be option-C
Explanation:
The rhythm of the heartbeat is controlled by the pacemaker of the heart called the sino-atrial node.
The SA node generates action potentials which trigger the contraction and relaxation of the atrium and ventricles. The membrane potential generation initiates by the depolarization of the cell membrane when the L type of Ca⁺² ions opens up and calcium ions enter the cell.
This depolarizes the cell until the potential threshold is reached which lies between the -40 and -30 mV.
Thus, Option-C is the correct answer.
Answer: The calcium ion binds to troponin, and this slides the tropomyosin rods away from the binding sites.
Explanation:
Contraction and relaxation of muscle cells brings about movements of the body. The contractile myofilament called sarcomeres are bounded at each end by a dense stripe called the Z - line, to which the myosin fibres are attached, and lying in the middle of the sarcomere are the actin filaments, overlapping with the myosin.
When action potential spreads from the nerve along the sarcolemma (muscle cell membrane), it penetrates deep into the muscle cell through the sarcoplasm (cytoplasm of muscle cell), and releases CALCIUM from the intracellular stores.CALCIUM triggers the binding of myosin to the actin filament next to it forming CROSS BRIDGES.
For this to occur, ACTIN BINDING SITE has to be made available. TROPOMYOSIN is a protein that winds around the chains of the actin filament and covers the myosin-binding sites to prevent actin from binding to myosin. The first step in the process of contraction is for calcium ions to bind to troponin so that tropomyosin can slide away from the binding sites on the actin strands.
The correct answer is - Its electrons are used to form NADPH.
On receiving light energy, electrons are expelled from the reaction center of photosystem II. The expelled electrons finally reduces oxidized NADH⁺ to NADH. The oxidized reaction center of photosystem II split water into protons, electrons and oxygen. The electrons released from water reduces oxidized reaction center of photosystem II. Thus, oxidized reaction center of photosystem II gets back its expelled electrons. Therefore, electrons from water forms NADH.
Answer:
4 × 10^0 kg or 4×E0 kg.
Explanation:
Before delving into or solving the Calculation, let us check one or two things about worker bees.
WHAT IS A WORKER BEE?.
Bees generally are social insects living in an organized community and they consist of three castes which include; the drone bees, worker bees, and the queen bees.
The queen bees are the female bees while the drone bees are the male bees.
The WORKER BEES are female bees too, but the only difference between them and the queen bees is that they (worker bees) do not reproduce like the queen bees. They are saddled with the responsibility of looking for food and maintaining the hive temperature.
Now to the question, the mass of a bee= 1 × 10^-4 kg. And there are 4 × 10^4 bees in hive. Therefore, the mass of all the worker bees in the hive together = (1 × 10^-4) × (4×10^4).
==> 4 × 10^0 kg, or 4E0 kg.
