<span>Dr. Jack Horner's discovery shower that dinosaurs and the very first birds lived at the same time. He noticed similarities in their features and habitat. This supported his hypothesis and later proved that birds evolved form dinosaurs.</span>
Answer:
a) to provide NADPH for reductive biosynthesis and for dealing with oxidative stress
d) to provide ribose-phosphate for nucleotide and nucleic acid biosynthesis
Explanation:
During the pentose phosphate pathway, glucose 6-phosphate is oxidized into pentose phosphates. This pathway uses NADP as an electron acceptor and reduces it into NADPH. The products of this pathway, the pentose phosphates are used by the cells to synthesize nucleic acids (DNA and RNA). The pentose phosphates are also used for the synthesis of nucleotides and coenzymes such as NADH, FADH2, etc.
These synthetic pathways are particularly occurring at a higher rate in the rapidly dividing cells such as the cells of bone marrow, skin. The NADPH formed during this pathway is used by cells as an electron donor for the reactions of reductive biosynthesis. Some of these pathways are the synthesis of fatty acids, cholesterol and steroid hormones. NADPH is also involved in scavenging reactive oxygen species such as oxygen radicals. These ROS are responsible for oxidative stress.
The statement, <em>“Bacteria set the stage for other life forms to evolve on earth” </em>was made probably because Earth was populated exclusively by single-celled organisms (Archaea and Bacteria) at the time that it was oxygenated, and only one of these can perform photosynthesis that separates a water molecule and results in oxygen gas, which is called Cyanobacteria, which has a blue-green color that comes from chlorophyll. Today, Cyanobacteria can practically be found everywhere on Earth, possibly in the soil right outside your door, and still play a vital role in producing the oxygen that we breathe. Another reason could be, billions of years ago, single-celled creatures had the planet to themselves. Then, they established different ways for cells to share and communicate resources. These intricate and complex multicellular creatures were the very first animals, and they were totally a major success. Consequently, animal life evolved about 540 million years ago.
Explanation:
<u>anaerobic process that restores NAD+ supply
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Within cells, aerobic respiration may not occur due to several factors:
- - a lack of inorganic, final electron acceptors
- -incomplete or lack of a complete electron transport system
- -missing genes for enzymes within the Kreb's cycle
Thus, they utilize other means for the generation of energy in the form of ATP and to replenish NAD+ an oxidized form of NADH, the main electron carrier in glycolysis. Pyruvate is produced in the cytoplasm via glycolysis- it is also used as an electron acceptor in a process called fermentation.
Further Explanation:
overall: C6H12O6 (glucose) + 6 O2 → 6 CO2 + 6 H2O + ≈38 ATP
In all eukaryotic cells mitochondria are small cellular organelles bound by membranes, these make most of the chemical energy required for powering the biochemical reactions within the cell. This chemical energy is stored within the molecule ATP which is produced. Respiration in the mitochondria utilizes oxygen for the production of ATP in the Krebs’ or Citric acid cycle via the oxidization of pyruvate( through the process of glycolysis in the cytoplasm).
Oxidative phosphorylation describes a process in which the NADH and FADH2 made in previous steps of respiration process give up electrons in the electron transport chain these are converted it to their previous forms, NADH+ and FAD. Electrons continue to move down the chain the energy they release is used in pumping protons out of the matrix of the mitochondria.
This forms a gradient where there is a differential in the number of protons on either side of the membrane the protons flow or re-enter the matrix through the enzyme ATP synthase, which makes the energy storage molecules of ATP from the reduction of ADP. At the end of the electron transport, three molecules of oxygen accept electrons and protons to form molecules of water...
- Glycolysis: occurs in the cytoplasm 2 molecules of ATP are used to cleave glucose into 2 pyruvates, 4 ATP and 2 electron carrying NADH molecules. (2 ATP are utilized for a net ATP of 2)
- The Citric acid or Kreb's cycle: in the mitochondrial matrix- 6 molecules of CO2 are produced by combining oxygen and the carbon within pyruvate, 2 ATP oxygen molecules, 8 NADH and 2 FADH2.
- The electron transport chain, ETC: in the inner mitochondrial membrane, 34 ATP, electrons combine with H+ split from 10 NADH, 4 FADH2, renewing the number of electron acceptors and 3 oxygen; this forms 6 H2O, 10 NAD+, 4 FAD.
Learn more about cellular life at brainly.com/question/11259903
Learn more about cellular respiration at brainly.com/question/11203046
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