Portage Learning BIOD 101 Modules 1, 2,3,4,5, and 6 | Actual Exam Tests Questions With Verified Answers

Portage Learning BIOD 101 Modules 1, 2,3,4,5, and 6 | Actual Exam Tests Questions With Verified Answers What is matter and what states can it exist in? - ANSWER Matter is anything that takes up space, by having volume, and has mass. Can exist in a solid, liquid, or gaseous state. Explain the difference between essential and trace elements - ANSWER Essenti al elements are required for human life. Trace elements are only required in small quantities Describe an ionic bond - ANSWER formed when ions of molecules of opposite charge are attracted to one another Describe a covalent bond - ANSWER formed when el ectrons are shared equally between two atoms to complete the valence shells of both Describe a hydrogen bond - ANSWER formed by electrostatic interactions between molecules - relatively weak and breaks easily True or False: Anions are positive charged io ns whereas cations are negatively charged ions. - ANSWER False: cations are positively charged ions whereas anions are negatively charged ions Which of the following is not one of the organic compounds that make up a biomacromolecule; lipids, proteins, r ibosomes, or carbohydrates - ANSWER Ribosomes What are carbohydrates? - ANSWER Carbohydrates are sugar molecules that serve as the main source of energy for organisms. Carbon, hydrogen and oxygen are the same three elements in their structure. Why are lipids unique among the biomacromolecules? - ANSWER They are unique because most of them are insoluble in water. Lipids also are not monomers and instead are assembled from smaller molecules that are chemically linked together Why are lipids insoluble in water? - ANSWER Lipids are insoluble in water because they are made of non polar hydrocarbon chains. Water is polar meaning that it can only dissolve other polar or ionically bonded substances. How are phospholipids arranged? - ANSWER Phospholipids are made up of a hydrophilic head and a hydrophobic tail. Describe the structure of a phospholipid. - ANSWER A phospholipid contains two main components (1) a polar head group joined to (2) a non -polar tail group. The head group is composed of a charged pho sphate group and ( usually ) a nitrogen - containing group. The head is attracted to polar substances, such as water, and is therefore hydrophilic ( water loving ). The tail group is a hydrocarbon ( a molecule containing H and C ) composed of non -polar fatt y acid chains. The gain repels water and is therefore hydrophobic ( water fearing ). The head group faces the outer environment and interacts with other polar molecules, while the tail group faces the inside of the cell, forming a double layered sheet. Name the functions of proteins as mentioned in the module - ANSWER Can act as enzymes and regulate metabolic functions, store amino acids, act as hormones, form antibodies for immunological defense, act as carriers for transport and the formation of membran e channels, form cell surface receptors to receive chemical messages, and act as structural molecules for support and movement How does the shape of a protein influence its function? - ANSWER Proteins are constructed from monomers called amino acids. The number and sequence of amino acids determines the shape, size, and function of the protein. How a protein functions or performs it's job is primarily based off the shape of the protein. What are the roles of the two major types of nucleic acids? - ANSWER DNA and RNA are the two major types of nucleic acids. DNA is responsible for giving living organisms inheritable characteristics. RNA is responsible for decoding the genetic information in DNA and using it to synthesize proteins. Describe the struc ture of DNA and RNA - ANSWER DNA and RNA present themselves as chains of nucleotides. RNA is most commonly a single chain of nucleotides whereas DNA is a double chain held together by hydrogen bonds between bases. Or DNA and RNA exist as chains of nucl eotides. DNA is a double chain held together by base pairs joined by hydrogen bonding. The structure of DNA resembles a spiral staircase due to its double strand. The four bases are A,C,T and G. RNA also spirals like DNA but unlike DNA it is commonly a sin gle chain of nucleotides. RNA also has base pairs but they are G,C,U and A. What are some main differences between prokaryotic and eukaryotic cells? - ANSWER Prokaryotic: considered simple cells and are defined by size, non -enclosed genetic material, and a lack of organelles Eukaryotic: cells more complex, larger in size, possess a nuclear membrane, and contain membrane bound organelles What organelles of the cells are complexes of tiny manufacturing plants that assemble proteins? - ANSWER Ribosomes What three types of protein fibers make up the cytoskeleton - ANSWER Microtubules, Microfilaments, and Intermediate filaments Which type of cell junctions are mechanical structures that wrap around the cell to prevent extracellular fluid from leaking - ANSWER Tight junctions What is the purpose of the cell membrane? - ANSWER The cell membrane provides protection for the cell. It encloses the cells cytoplasm and organelles and separates the extracellular environment ( external environment ) from the inte rcellular environment ( internal cellular environment ). Explain the main difference between passive and active transport and provide an example of each. - ANSWER Passive transport occurs when substances move through the membrane without the input of ene rgy. Examples include simple diffusion, osmosis, filtration, and facilitated diffusion. Active transport occurs when an input of energy is required to move substances through the membrane. An example is the sodium -potassium pump. Why is the electrochemica l gradient important for cellular function? - ANSWER The electrochemical gradient is important for cellular function because with it cells are able to control the direction ions move across the membrane. The electrical potential of ions across the cell me mbrane is an important factor for nerve