In human audition, the vibration of the ossicles is triggered by the vibration of the tympanic membrane (the eardrum) and transmitted directly to the fluid and membranes of the inner ear.
The inner ear is shaped like a snail with a thousands of tiny hair cells in it and it is called the cochlea. Hair cells change the vibrations into electrical signals that are sent to the brain through the auditory nerve.
Answer:
The expected results could be explained in different ways.
Explanation:
When the results of the investigation tell a different story from the proposed investigation, that is not related to the hypothesis or research topic, it is advisable that the scientist changes their hypothesis to fit the investigation outcome.
Explanation:
-Pheophytin
P680 the primary donor of Photosystem II becomes excited and transfers an electron to pheophytin. Pheophytin is the initial intermediate electron acceptor and carrier in Photosystem II; it is a chlorophyll-like molecule that lacks a central magnesium ion.
Further Explanation:
Photosynthesis is a chemical pathway that’s integral to producing energy in plants and other primary producers. Energy in the form of molecules of glucose is produced from light, water and carbon dioxide while oxygen is released. This occurs in several complex steps, photosynthesis is a rate limited reaction, depends on several factors including carbon dioxide concentration, ambient temperature and light intensity; the energy is retrieved from photons, I.e. particles of light, and water is used as a reducing agent. This occurs in the thykaloids, where pigment molecules like chlorophyll reside.
The chloroplast is a membrane bound organelle found in plants. It contains several invaginations of a plasma membrane called the thylakoid membrane. This contains chlorophyll pigments, in stacks called granum, while the internal spaces of the organelle are called the lumen. Liquid surrounds the granum, forming the stroma.
During the light reaction:
- Light is absorbed by pigments in phosystem II (PSII). This energy is transferred among pigments til it gets to the reaction center, and is transferred to P680; this promotes an electron to a higher energy level where it then goes to an acceptor molecule, like Pheophytin .
- Water supplies the chlorophyll in plant cell with replacement electrons for the ones removed from photosystem II. Additionally, water (H2O) split by light during photolysis into H+ and OH- acts as a source of oxygen along with functioning as a reducing agent.
- the electron moves down an electron transport chain (to PS I)where it experiences continuous energy loss. This energy fuels the pumping of H+ from the stroma to thykaloid, leading to the formation of a gradient. The H+ move along their gradient and cross through ATP synthase, into the the stroma.
- ATP synthase converts ADP and Pi to the energy storage molecule ATP.
- The electron gets to photosystem I where it goes to pigments at P700. It absorbs light energy, the electron is promoted to a higher energy level, and passed to an electron acceptor. This leaves a space for another electron which is then replaced by one from photosystem II.
- in the ETC, the molecule NADP is reduced to NADPH by providing H+ ions. NADP and NADPH are integral to the Calvin cycle where monosaccharides or sugars like glucose are produced after the modification of several molecules.
Learn more about Photosynthesis at brainly.com/question/4216541
Learn more about cellular life at brainly.com/question/11259903
#LearnWithBrainly
Answer:
A. Molecular changes such as extracellular signals on extracellular ligands can result in quick changes in cell behaviour. One example is insulin. Upon insulin binding on the receptor on the cell membrane, the cell release GLUT4 transporters (for muscle cells) to increase uptake of glucose.
B. Slow changes in cell behaviour can be observed for other lipophilic hormones or intracellular receptors such as glucocoortoid or estrogen which reacts with receptors in the cells.
C. Insulin is required to maintain a constant blood glucose level and hence levels of insulin has to be mediated in correspondence to the blood glucose levels. Fast acting signalling is thus required for homeostasis of blood glucose levels. Where for such lipophilic hormones such as steriods, glucocortoid, these hormones tend to have a longer lasting effect and hence results in a slow change.
