6,7,9,13
Contrasts the two mechanisms for producing ATP and their relative efficiency.
1- Contrasts the two mechanisms for producing ATP and their relative efficiency. Single molecule of glucose upon oxidation give rise to carbon dioxide and water molecule and cell makes about 36or 38 ATP molecules. There are two basic mechanism by cell makes ATP upon oxidation of glucose molecule. 1. Substrate level phosphorylation: It is a direct transfer of phosphate with the help of enzyme to ADP through substrates. For example: Production of ATP from substrate PEP(phoshphoenol pyruvate) and ADP, pyruvate kinase enzyme used. very small percentage of ATP is produced in this way. 2. Oxidative phosphorylation: it is one of the mechanism of major production of ATP by transfer of electrons from NADH or FADH2 to oxygen molecule through of electron carriers in presence of proton gradient. This reaction happened in mitochondria the power house of cell. For example: this reaction produces 26 out of 30 molecules of ATP when glucose completely oxidized to carbon dioxide and water molecules.
Describe the function of ATP in the cells and how it works.
ATP is able to power cellular processes by transferring a phosphate group to another molecule (a process called phosphorylation).
Distinguish the process and the outcomes between aerobic and anaerobic respiration
Aerobic respiration takes place in presence of oxygen; whereas anaerobic respiration takes place in absence of oxygen. Carbon dioxide and water are the end products of aerobic respiration, while alcohol is the end product of anaerobic respiration. Aerobic respiration releases more energy than anaerobic respiration.
Explain the implications of cell cycle control for multicellular organisms
All multicellular organisms use cell division for growth and the maintenance and repair of cells and tissues. Cell division is tightly regulated because the occasional failure of regulation can have life-threatening consequences. Single-celled organisms use cell division as their method of reproduction.
Describe the composition of chromatin and the structure of chromosomes
As mentioned above, chromatin is composed of DNA and histones that are packaged into thin, stringy fibers. The chromatin undergoes further condensation to form the chromosome. So the chromatin is a lower order of DNA organization, while chromosomes are the higher order of DNA organization
Describe the components and the structure of DNA and RNA
Both DNA and RNA are made from nucleotides, each containing a five-carbon sugar backbone, a phosphate group, and a nitrogen base. DNA provides the code for the cell 's activities, while RNA converts that code into proteins to carry out cellular functions.
Connect the factors of cell cycle control and cancer
Cancer is unchecked cell growth. Mutations in genes can cause cancer by accelerating cell division rates or inhibiting normal controls on the system, such as cell cycle arrest or programmed cell death. As a mass of cancerous cells grows, it can develop into a tumor
State the first and second laws of thermodynamics and explain how those laws relate to chemical processes.
Chemical thermodynamics is the portion of thermodynamics that pertains to chemical reactions. First law: Energy is conserved; it can be neither created nor destroyed. Second law: In an isolated system, natural processes are spontaneous when they lead to an increase in disorder, or entropy.
Distinguish between chromosomes and sister chromatids
Chromosomes are not the exact copies of one another. One copy of the gene comes from each parent to the organism. Sister chromatids, on the other hand, are identical copies of one another.
Interpret the role of electrons, electron carriers, and ATP in energy metabolism
Electrons are dropped off at the electron transport chain by the electron carrier molecules and as it is passed, molecules pump hydrogen ions across the membrane and generate an electrochemical gradient. The ATP sythase uses the hydrogen ion gradient to generate ATP.
Illustrate the purpose of the electron transport chain, where those electrons come from and where do they end up.
Electrons are obtained from the glucose molecule and carried by NADH and FADH. The final destination of the electrons is the oxygen atom. Oxygen plays the role of the last electron acceptor
Explain entropy.
Entropy is a measure of randomness or disorder in a system
Explain what free energy is and how it can be used to predict the energetic outcome of chemical reactions.
Free energy -The change of free energy that accompanies the formation of 1 mole of a substance in its standard state from its substrates in their standard conditions. The free energy is associated with a chemical reaction which states the nature of the reaction . If the free energy is lesser than zero, the reaction is spontaneous. If the free energy is greater than zero then the reaction is non - spontaneous and it has to be coupled with other reactions which releases energy. When free energy is zero then the reaction is in equillibrium.
List the phases and the events that occur at each phase of the interphase
Interphase is composed of G1 phase (cell growth), followed by S phase (DNA synthesis), followed by G2 phase (cell growth). At the end of interphase comes the mitotic phase, which is made up of mitosis and cytokinesis and leads to the formation of two daughter cells.
Explain the purpose of oxygen in respiration
Oxygen is required in the cellular respiration in the electron transporter chain. It serves as the final electron acceptor of the electron transport chain facilitating the movement of electrons down the chain hence producing the ATP or adenosine triphosphate.
Describe the events that occur at each phase of mitosis
Prophase - The chromosomes shorten and thicken. Metaphase - Chromosomes line up in the middle of the cell. Anaphase - Chromatids break apart at the centromere and move to opposite poles. Telophase - Two nuclei formed after nuclear envelopes reform around each group of chromosomes.
List the factors that affect enzyme activity.
Several factors affect the rate at which enzymatic reactions proceed - temperature, pH, enzyme concentration, substrate concentration, and the presence of any inhibitors or activators.
Explain why replication is semidiscontinuous in the lagging strand
Synthesis of the lagging strand has to be discontinuous because DNA polymerase cannot make a new strand in the 3' to 5' direction. Therefore, a series of Okazaki fragments, each with their own RNA primer, must be made as to the fork advances.
Explain the importance of telomeres for linear chromosomes
The ends of the linear chromosomes are known as telomeres: repetitive sequences that code for no particular gene. These telomeres protect the important genes from being deleted as cells divide and as DNA strands shorten during replication.
Describe the function of enzymes in biological reactions
The function of enzymes is to carry out critical tasks. These involve muscle growth, removing toxins, and tearing down the molecules in food throughout digestion.
Describe the process of DNA replication and the proteins involved
The initiation of DNA replication occurs in two steps. First, a so-called initiator protein unwinds a short stretch of the DNA double helix. Then, a protein known as helicase attaches to and breaks apart the hydrogen bonds between the bases on the DNA strands, thereby pulling apart the two strands.
Summarize the initial reactants, final products and outcomes of glycolysis, pyruvate oxidation and Krebs cycle. In this summary, track the carbons, the electrons and the ATP produced.
The ultimate purpose of the Krebs cycle is to oxidize acetyl CoA into carbon dioxide for the goal of creating high-energy intermediates to continue aerobic respiration. One molecule of pyruvate creates two carbon dioxide molecules, electrons, and one ATP molecule as products of the Krebs cycle.
Describe where in the cell and where in mitochondria each process of cellular respiration happens
There are three main steps of cellular respiration: glycolysis, the citric acid cycle, and oxidative phosphorylation. Glycolysis takes place in the cytosol, the citric acid cycle occurs in the mitochondrial matrix, and oxidative phosphorylation occurs on the inner mitochondrial membrane.
Describe the function of each element in the replication fork
There are two main activities occur during DNA replication at the fork, DNA unwinding and DNA synthesis. The enzyme helicase and DNA polymerase plays an important role at replication fork. Helicase enzyme helps in unwinding of of the unreplicated DNA ahead of it, it was shown in a study done by Gambus et al in 2009. Helicase helps to modify the structure of the DNA helix and promote unwinding and seperation of the two DNA strands. Later, DNA polymerase comes into play. this enzyme helps to link together and helps to polymerizes the DNA bases at correct sequence with the help of template DNA strand and helps to generate two copies of genome, later they are divided into two daughter cells in metaphase, according to a study done by Langston et al in 2009. To synthesize DNA, the double-stranded DNA is unwound by DNA helicases ahead of polymerases, forming a replication fork containing two single-stranded templates. Replication processes permit the copying of a single DNA double helix into two DNA helices, which are divided into the daughter cells at mitosis.
