Oxford University Press | Online Resource Centre | Multiple choice questions
Describe the relationships between structure and between prokaryotic and eukaryotic cells that . statement BEST describes the primary function of the. Which of the following statements about recombinant DNA molecules is true? .. Which statement best describes the relationship between eukaryotes and of prokaryotes: one with a close evolutionary relationship to eukaryotes and one. Living cells are of two major types, prokaryotes and eukaryotes. About 2 billion years ago only prokaryotes inhabited our world. The main.
The membranes of both the prokaryotic and the eukaryotic cell consist of a lipid bilayer. The origin of the membrane structures within the eukaryotic cell can be explained by an early large prokaryotic cell engulfing smaller prokaryotic cells, according to the endosymbiosis theory. The identical genetic code is used in prokaryotic and eukaryotic cells. Although the same kind of DNA is found in prokaryotic and eukaryotic cells, the DNA is naked and forms a loop or circle in prokaryotes, while it is composed of linear strands and covered with protein in eukaryotes.
Sciencing Video Vault Ribosomes Both prokaryotic and eukaryotic cells contain ribosomes. Ribosomes are made up of proteins and RNA and are the site of protein synthesis in both cell types.
The building blocks to make protein are amino acids. The prokaryotic and the eukaryotic cells use the same 20 amino acids to make proteins, indicating relatedness.
Mitochondria and Chloroplasts Eukaryotes contain mitochondria or chloroplasts. Mitochondria within animal cells and chloroplasts within plant cells look like prokaryotes.
Mitochondria and chloroplasts are similar in size and features to prokaryotes. The deep folds of the inner mitochondrial membrane, called cristae, resemble the folds in the prokaryotic cell, called mesosomes. The material was then analyzed by other scientists. Analysis showed that the chemical was composed of long chains of repeated CH2 molecules.
The CH2 molecular structure contained a negatively charged phosphate groups. Which statement BEST describes the primary function of the CH2 and phosphate molecular structure located in the plasma membrane?
It contains the genetic information needed for protein production. It allows the energy that a cell needs to perform various life processes. It allows a cell to regulate the movement of materials into and out of a cell. It catalyzes specific chemical reactions in the cytoplasm of a cell. Incorrect — The molecule describe does not indicate DNA. Incorrect — the molecule described does not indication an ATP molecule.
Correct — the molecule described is a phospholipid located in the plasma membrane that helps regulate the movement of materials into and out of a cell.
Chapter 2: Multiple choice questions
Incorrect - The molecule described does not indicate an enzyme. Lipid Protein Carbohydrate Nucleic acid 26 Answer - A Correct — most lipids have long hydrocarbon chains as the main component of their structures. The molecule describes also contains a phosphate group, indicating a phospholipid. Incorrect — Proteins are made of amino acids Incorrect — Nucleic acids are made of nucleotides Incorrect — carbohydrate molecules are made of carbon, hydrogen, and oxygen atoms in a specific ratio.
Proteins are a major part of every living cell and have many functions within each cell. Carbohydrates also perform multiple roles in living things. Describe the general composition of a protein molecule. Describe how the structures of proteins differ from the structures of carbohydrates.
Describe how the functions of proteins differ from the functions of carbohydrates. Proteins consist of carbon, hydrogen, oxygen, and nitrogen. These elements are combined to form over 20 different amino acids. These amino acids are then manipulated into four different levels of protein structure. Proteins contain nitrogen, while carbohydrates do not. The elements in carbohydrates are used to create ring- shaped monosaccharides, which are then strung together into di- and polysaccharides. There are only three different monosaccharides.
Evolutionary Relationships Between Prokaryotes & Eukaryotes | Sciencing
Proteins contain over 20 monomer units, the amino acid. Their four-level structure also makes them more complex. Due to their complex structure, proteins have a huge variety of function. Carbohydrates have a more simplistic structure and are used primarily for energy and structure. Describe the roles of an enzyme as a catalyst in regulating a specific biochemical reaction.
Explain how factors such as pH, temperature, and concentration levels can affect enzyme function. Which statement BEST describes the roles of an enzyme during this reaction? It adjusts the pH of the reaction medium. It provides energy to carry out the reaction.
Keystone Review Module A.
It dissolves substance A in the reaction medium. It speeds up the reaction without being consumed. Incorrect — not relevant to converting the substance. Incorrect — enzymes do not actually provide energy for reactions. Incorrect — enzymes do not dissolve substances. Correct — enzymes speed up the rate of chemical reactions by lowering the activation energy needed to start the reaction. Enzymes are not used up by this, and can be reused.
A pH change can cause the enzyme to change its shape. A pH change can remove energy necessary to activate an enzyme. A pH change can add new molecules to the structure of the enzyme.
A pH change can cause an enzyme to react with a different substrate. Changes in pH, temperature causes the proteins that make-up the enzyme to denature. This changes their shape and prevents them from catalyzing reactions. Incorrect — enzymes do not actually provide energy for the reaction. Incorrect — pH change does not add molecules to the enzyme Incorrect — a denatured enzyme will not react with anything.
The diagram models how a poison bonds to the active site of an enzyme. The release of stored chemical energy. The donation of electrons to the substrate The supply of activation energy for a reaction. The catalysis of the reaction with the substrate. Incorrect - Enzymes do not donate electrons to the substrate. Incorrect — Enzymes lower the activation energy needed for the chemical reaction to occur. Correct — Most enzymes react with only one reactant, so when a poison blocks the active site, the enzyme can no longer bond with the substrate, causing the chemical reaction to stop.
The enzyme is used up and the reaction stops. The graph shows how the activity of an enzyme changes at different temperatures. Which statement BEST describes what happens to the enzyme when the temperature of the reaction increases to 45 degrees? The enzyme begins to decrease the rate of the reaction. The enzyme continues to increase the rate of the reaction. The enzyme changes shape and can no longer speed up the reaction.
Incorrect — the enzyme does not have the ability to decrease the rate of a reactions; the rate of reaction is affected by temperature, pH, concentration, etc. Incorrect — The graph illustrates that enzyme activity decreases as the temperature increases beyond 40 degrees.
Correct — enzymes have an optimum temperature range at which they function; when the temperature exceeds that range, the enzyme will denature, causing it to change shape and no longer be able to bind to the substrate. Describe the fundamental roles of plastids and mitochondria in energy transformations. ATP to light Light to chemical Heat to electrical Chemical to chemical 42 Answer - B Incorrect — chloroplasts make ATP to use during photosynthesis using light energy Correct — chloroplasts use light energy to create chemical energy in the form of glucose.
Incorrect — heat energy is not a part of photosynthesis Incorrect — the energy coming in to photosynthesis is light energy. Compare the basic transformation of energy during photosynthesis and cellular respiration. Describe the role of ATP in biochemical reactions. Which statement correctly describes one similarity between photosynthesis and cellular respiration? Both occur in animal and plant cells.