Answer the following question given this paragraph: The rates at which chemical reactions take place in organisms are very important. Chemical reactions in organisms are involved in processes ranging from the contraction of muscles to the digestion of food. For example, when you wave goodbye, it requires repeated contractions of muscles in your arm over a period of a couple of seconds. A huge number of reactions must take place in that time, so each reaction cannot take longer than a few milliseconds. If the reactions took much longer, you might not finish waving until sometime next year. Q: What kind of reactions are involved in processes ranging from the contraction of muscles to the digestion of food? Choices: - liquid - atomical - mineral - chemical A:
chemical
(Question)
Answer the following question given this paragraph: Q: What is the spread of cancer cells beyond their original site called? Choices: - scattering - mutations - apoptosis - metastasis A:
(Answer)
metastasis
Ques: Answer the following question given this paragraph: In a wheel and axle, force may be applied either to the wheel or to the axle. This force is called the input force. A wheel and axle does not change the direction of the input force. However, the force put out by the machine, called the output force, is either greater than the input force or else applied over a greater distance. Q: What is the term for the force applied to a wheel and axle? Choices: - velocity force - momentum - output force - input force A:
Ans: input force
(Q).
Answer the following question given this paragraph: To understand the differences between nuclear fission and fusion. Nuclear reactions, like chemical reactions, are accompanied by changes in energy. The energy changes in nuclear reactions, however, are enormous compared with those of even the most energetic chemical reactions. In fact, the energy changes in a typical nuclear reaction are so large that they result in a measurable change of mass. In this section, we describe the relationship between mass and energy in nuclear reactions and show how the seemingly small changes in mass that accompany nuclear reactions result in the release of enormous amounts of energy. Q: The energy changes in what reactions are enormous compared with those of even the most energetic chemical reactions, and they result in a measurable change of mass? Choices: - molecular reaction - metabolic reaction - methane combustion - nuclear reactions A:
(A).
nuclear reactions
Ques:Answer the following question given this paragraph: Glycolysis You have read that nearly all of the energy used by living things comes to them in the bonds of the sugar, glucose. Glycolysis is the first step in the breakdown of glucose to extract energy for cell metabolism. Many living organisms carry out glycolysis as part of their metabolism. Glycolysis takes place in the cytoplasm of most prokaryotic and all eukaryotic cells. Glycolysis begins with the six-carbon, ring-shaped structure of a single glucose molecule and ends with two molecules of a three-carbon sugar called pyruvate. Glycolysis consists of two distinct phases. In the first part of the glycolysis pathway, energy is used to make adjustments so that the six-carbon sugar molecule can be split evenly into two three-carbon pyruvate molecules. In the second part of glycolysis, ATP and nicotinamide-adenine dinucleotide (NADH) are produced (Figure 4.13). If the cell cannot catabolize the pyruvate molecules further, it will harvest only two ATP molecules from one molecule of glucose. For example, mature mammalian red blood cells are only capable of glycolysis, which is their sole source of ATP. If glycolysis is interrupted, these cells would eventually die. Q: Which process breaks down glucose to extract energy for cell metabolism? Choices: - photosynthesis - meiosis - mitosis - glycolysis A:

Ans:glycolysis
Ques: Answer the following question given this paragraph: produced in cells located in the stomach wall. When food enters the stomach after a period of fasting, pepsinogen is converted to its active formpepsinin a series of steps initiated by the drop in pH. Pepsin catalyzes the hydrolysis of peptide linkages within protein molecules. It has a fairly broad specificity but acts preferentially on linkages involving the aromatic amino acids tryptophan, tyrosine, and phenylalanine, as well as methionine and leucine. Protein digestion is completed in the small intestine. Pancreatic juice, carried from the pancreas via the pancreatic duct, contains inactive enzymes such as trypsinogen and chymotrypsinogen. They are activated in the small intestine as follows (Figure 20.7 "Activation of Some Pancreatic Enzymes in the Small Intestine"): The intestinal mucosal cells secrete the proteolytic enzyme enteropeptidase, which converts trypsinogen to trypsin; trypsin then activates chymotrypsinogen to chymotrypsin (and also completes the activation of trypsinogen). Both of these active enzymes catalyze the hydrolysis of peptide bonds in protein chains. Chymotrypsin preferentially attacks peptide bonds involving the carboxyl groups of the aromatic amino acids (phenylalanine, tryptophan, and tyrosine). Trypsin attacks peptide bonds involving the carboxyl groups of the basic amino acids (lysine and arginine). Pancreatic juice also contains procarboxypeptidase, which is cleaved by trypsin to carboxypeptidase. The latter is an enzyme that catalyzes the hydrolysis of peptide linkages at the free carboxyl end of the peptide chain, resulting in the stepwise liberation of free amino acids from the carboxyl end of the polypeptide. Figure 20.7 Activation of Some Pancreatic Enzymes in the Small Intestine. Q: When food enters the stomach after a period of fasting, a drop in what initiates the conversion of pepsinogen to pepsin? Choices: - calcium - white blood cells - acid - ph A:
Ans:
ph