Answer:
The preceding section reviewed the major metabolic reactions by which the cell obtains and stores energy in the form of ATP. This metabolic energy is then used to accomplish various tasks, including the synthesis of macromolecules and other cell constituents. Thus, energy derived from the breakdown of organic molecules (catabolism) is used to drive the synthesis of other required components of the cell. Most catabolic pathways involve the oxidation of organic molecules coupled to the generation of both energy (ATP) and reducing power (NADH). In contrast, biosynthetic (anabolic) pathways generally involve the use of both ATP and reducing power (usually in the form of NADPH) for the production of new organic compounds. One major biosynthetic pathway, the synthesis of carbohydrates from CO2 and H2O during the dark reactions of photosynthesis, was discussed in the preceding section. Additional pathways leading to the biosynthesis of major cellular constituents (carbohydrates, lipids, proteins, and nucleic acids) are reviewed in the sections that follow.
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Carbohydrates
In addition to being obtained directly from food or generated by photosynthesis, glucose can be synthesized from other organic molecules. In animal cells, glucose synthesis (gluconeogenesis) usually starts with lactate (produced by anaerobic glycolysis), amino acids (derived from the breakdown of proteins), or glycerol (produced by the breakdown of lipids). Plants (but not animals) are also able to synthesize glucose from fatty acids—a process that is particularly important during the germination of seeds, when energy stored as fats must be converted to carbohydrates to support growth of the plant. In both animal and plant cells, simple sugars are polymerized and stored as polysaccharides.
Gluconeogenesis involves the conversion of pyruvate to glucose—essentially the reverse of glycolysis. However, as discussed earlier, the glycolytic conversion of glucose to pyruvate is an energy-yielding pathway, generating two molecules each of ATP and NADH. Although some reactions of glycolysis are readily reversible, others will proceed only in the direction of glucose breakdown, because they are associated with a large decrease in free energy. These energetically favorable reactions of glycolysis are bypassed during gluconeogenesis by other reactions (catalyzed by different enzymes) that are coupled to the expenditure of ATP and NADH in order to drive them in the direction of glucose synthesis. Overall, the generation of glucose from two molecules of pyruvate requires four molecules of ATP, two of GTP, and two of NADH. This process is considerably more costly than the simple reversal of glycolysis (which would require two molecules of ATP and two of NADH), illustrating the additional energy required to drive the pathway in the direction of biosynthesis.
The answers would be:
Genotype Phenotype
Tt Tall stemmed
tt Short stemmed
Genotypic ratio : 2:2 or 1:1
Phenotypic ratio: 2:2 or 1:1
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<u>You can read on to see how this was done:</u>
Tall stems (T) are dominant to short stems (t).
First figure out the genotypes of the parents. We have a short-stemmed plant and a heterozygous long-stemmed plant cross.
For short stem to occur, you need 2 pairs of short alleles. So the first parent would have a genotype of tt.
Heterozygous long-stemmed means that the parent has one of each allele. So the genotype of the second parent would be, Tt.
Now we can make our Punnett Square.
tt x Tt
<u> t t </u>
<u>T | Tt | Tt</u>
<u>t | tt | tt</u>
Let's list down the genotypes and phenotypic results.
Genotype no. Phenotype
Tt 2 Tall stemmed
tt 2 Short stemmed
So from that we can answer the other questions:
Genotypic ratio : 2:2 or 1:1
Phenotypic ratio: 2:2 or 1:1
The answer is <span>Fish are ectothermic and lay eggs to reproduce, while mammals are endothermic and give live birth to offspring.
Through the elimination process:
</span><span>* Fish are <u>invertebrates</u> and have scales and paired fins, while mammals are vertebrates and have fur or hair. - Fish are vertebrates!
</span><span>* Fish are <u>endothermic</u> and have gills, while mammals are <u>ectothermic</u> and have lungs. - Fish are ectothermic (cold-blooded), and mammals are endothermic (warm-blooded)!
</span>* <span>Fish have streamlined bodies and <u>three-chambered hearts</u>, while mammals are <u>bipedal</u> and have four-chambered hearts. - Fish have four chambered hearts and not all mammals are bipedal!
This leaves choice: </span><span>Fish are ectothermic and lay eggs to reproduce, while mammals are endothermic and give live birth to offspring. All of this is true, but it should be taken into consideration that some fish give live birth and some mammals lay eggs, but this is the most possible choice among all mentioned.</span>
Answer:
False
Explanation:
The sequence of amino acids in a protein is determined by the DNA and the structure of protein thus formed is a linear sequence. These linear structures undergo structural changes due to the formation of bonds between the constituent molecules.
When bonds are formed by the interactions between the CO group of one chain and the -H group which forms the backbone is known as the secondary structures. Two types of arrangements arise of this that is the helical and pleated sheet.
When the bonds are formed between the side groups or the R group of the amino acid therefore the amino acid structure formed is known as the tertiary structure.
Thus, false is the correct answer.
