Thursday, December 12, 2019
Biological Characteristics of Life
Question: Understand the Characteristics of life in relation to the human body. Understand the human cell. Understand metabolism in the human cell. Understand enzymes within the human body. Understand transport in and out of cells. Understand Adenosine Triphosphate (ATP) in the human. Answer: Discuss the biological characteristics of life Basically, there are seven biological characteristics that are required for human body survival that is discussed below. Cellular organization The basic unit of survival is cell where all the activities of life processes take place. The cells are the basic machinery for different living activities and, therefore, cellular organization made by a compilation of these cells is the most important component of the human body (Buchanan, 2010). Reproduction For continuity of survival, the reproduction is required to produce new living organism by the process of sexual reproduction in the human body. Reproduction is the only characteristic that leads to the formation of a new living organism. Metabolism The metabolism process is the collaboration of all chemical reactions occurring in the cell for maintaining life in the body. Basically, metabolism is functioning of cellular components and therefore, no cellular activity is possible without metabolism (Alberts et al. 2013). Homeostasis This is a biological characteristic that is required to maintain the equilibrium in internal atmosphere of the body. This included body temperature, pressure, acidity, alkalinity etc. Heredity Heredity is the transfer of traits from parent to offsprings and it important for continuity of trait from one human generation to another that will lead to evolution and adaptation in human species (Buchanan, 2010). Evolution and adaptation Evolution and adaptation are the important biological characteristics of the human body to survive with the external environment and develop response according to the external environment. Growth and development The biological characteristics of growth and development are important for quality and longevity of human survival (Alberts et al. 2013). Discuss in detail the structure and the functions of a human cell using a diagram Human cell diagram (Diagram attached as separate file) Some peripheral proteins form markers or antigens on the surface of the plasma membrane of some specialised cells, explain in detail their role? Peripheral proteins working as marker or antigen on plasma membrane are actually the proteins extended across the plasma membrane that function as an identifier of the cell. The antibodies of body immune system identify these marker proteins to distinguish body cells or friendly cells from foreign invaders. These marker proteins work as fingerprints of the cell. These proteins also function as antigen for the antibodies of the immune system (Chan and Marshall, 2010). Marker proteins play a major role in organ transplantations where the rejection or acceptance of transplant depends on correct marker protein identification of the cell by the immune system. If the marker proteins of transplanted organs are different from original organ than the body immune system rejects the transplant (Richards et al. 2012). How does the phospholipid bi-layer arrangement of the plasma membrane assist with the movement of substances through the membrane? The phospholipid bilayer of the plasma membrane is a thin flexible layer that consists of different components like lipid bilayer, proteins, fatty acids, and carbohydrates. There are two categories of protein on bilayer that are peripheral and internal proteins. Out of these, the internal protein arrangements on phospholipid bilayer functions to form a channel for the movement of materials through the membrane. These internal proteins form a channel between the lipid bilayer for substance movement (Phillips et al. 2012). Below are micrographs of two cell organelles; identify each organelle, and discuss in detail their interrelationship with each other? A) The provided organelle is Mitochondria that is a double layered organelle found in eukaryotic cells working as the powerhouse of the cell. B) The provided organelle is Golgi apparatus or Golgi body found in eukaryotic cells that function basically for transportation and resides at the intersection of endocytic, lysosomal and secretory pathways. Interrelationship of Mitochondria and Golgi apparatus Mitochondria produces energy in the form of ATP in the cell that energy is further operated by DNA and supplied to different organelles for various cellular processes. The Golgi apparatus uses this energy for processes of endocytosis and exocytosis (Westermann, 2010). Further, Golgi apparatus functions as one part of the transportation machinery for the products of the mitochondria inside the cell. After apoptosis of mitochondria, it undergoes cellular digestion and is transported by membrane surface by Golgi complex (Vasudevan et al. 2010). Discuss the role of ribosomes in protein synthesis giving examples? Ribosomes are macromolecular organelles that consist of rRNA and polypeptide chain made up of two basic subunits that are the 40s and 60s in eukaryotic cells. The ribosomes function as protein synthesis factory or workhorses. They are basically involved in the translation process of protein synthesis where mRNA after transcription gets translated to polypeptide chain further forming proteins. Basically, the different codons of mRNA are translated to different amino acids attached to tRNA forming polypeptide chain supported by ribosomes. For example- AUG codon forms methionine, UCU forms serine, CAC forms histamine etc. (Hardesty and Kramer, 2012). The mRNA codon (shine-Dalgarno) required for translation initiation is identified by ribosome where ribosome gets attached to mRNA. For example, the mRNA sequence of AUG is identified by rRNA codon UAC in the 40s unit of ribosomes that gets attached to mRNA (Koren and Torchilin, 2012). Further, ribosome provided a proper biological environment and three different sites for the attachment of mRNA and tRNA molecules. These sites on ribosome are named as A, P and E where A-site is attachment site of aminoacyl-tRNA, p site is for attachment of peptidyl-tRNA and E-site is for free tRNA before it leaves the ribosome. Ribosome also provides structural support and catalyst required for protein synthesis (Gagnon et al. 2012). Discuss the role of lysosomes in `autolysis`? Lysosomes are membrane bound structures or waste disposal system in the cell that contains hydrolytic enzymes that are capable to breakdown all categories of biomolecules including proteins, lipids, carbohydrates and nucleic acids. In living organism the autolysis is a phenomenon leading to self-digestion or cellular destruction that it initiated by the digestive enzymes released from lysosomes into the cytoplasm. Therefore, lysosomes functions as precursor and supplier for the process of autolysis (Holtzman, 2012). Discuss the transmission of hereditary traits by genes? Every living organism consists nuclear material known, as DNA inside the nucleus that carries hereditary characteristics or traits in the form of nucleotide base pairs sequences knows as genes. Each trait has its specific gene sequence on DNA molecules. The chromosomes inside the nucleus containing DNA get replicated into two identical copies in the process of reproduction. Each chromosome copy carries thousands of genes similar to parent genes that were found in parent chromosome. The two identical copies get separated and get transmitted to offspring from a parent through reproduction. In this manner, gene work as the basic unit that carry hereditary traits from one generation to another generation. These genes work as codes of a specific character that offsprings inherit from their parents (Baginsky et al. 2010). Explain how cells are organised to form other structures in the human body A) Skeletal Muscle Tissue The diagram is skeletal muscle fibres that form skeletal muscle tissue or voluntary muscle in the body. An average male consist 42% skeletal muscle and average female contains 36% skeletal muscle in the body. These muscle tissues are formed by the combination of muscle cells that contains myoblasts formed of myofibrils. The diagram shows various myofibrils combined together with the mitochindrias in between. The main function of muscle fibrils is related to cellular physiology and contraction. The muscle fibrils contain actin and myosin along with various other components that lead to muscle contraction and relaxation forming movement in the body in the presence of nerve impulses and ATP the myosin and actin function to breakdown ATP into ADP and phosphate molecules. The energy released after this process gets stored in myosin that is further utilized in the later movement of the body. These muscle tissues maintain the posture and body position because contraction supports particular position. Further, these tissues also play an important role in the movement of materials inside the body by the signalling process (Pedersen and Febbraio, 2012). B) Connective Tissue- Compact Bone Matrix The diagram is of the compact bone matrix that contains a central canal surrounded by lamellae of calcified matrix further surrounding blood vessels. These concentric circles develop compact bones. The lamellae are growth rings that increase in number with age. These compact bone provides structural support, structure and strength to body. These tissues also function for the protection of cancellous bone containing marrow. Compact bone is almost present in all bones of the body. These tissues also releases hormones to encourage mineralization forming solid bones. Proper balance in blood calcium and other tissues is also supported by compact bone matrix (Herring, 2012). C) Nervous Tissue - Neuron The diagram represents neuron known as nerve cell that can be electrically excited for transmission of information or signals from body to brain or from brain to the body. The neurons are functional unit of nervous system signalling pathway where different sub-structures of neuron perform different functions (Alivisatos et al. 2013). The dendrites transfer information to body cells in the form of electric impulses. Axon works as a conduit for information or signal flow between brain regions. At axon terminal process of synapses occurs where electric impulse releases neurotransmitters (chemicals) that convey information to cells of the body in a form of these chemicals (Finch, 2010). Explain the terms metabolism, catabolism and anabolism with reference to the human cell Metabolism Metabolism is the word used to for all the chemical reactions occurring inside the living cell to maintain the living state of the cell as well as the organism. Metabolism is basically the chemical transformations that occur inside cells of all living creatures basically involved in the production of energy leading to cellular activities, breakdown of food into proteins, lipids, carbohydrates and elimination of waste from the body. Anabolism and catabolism are two categories of metabolic activity occurring in the human body (DeBerardinis and Thompson, 2012). One of the most common example, of metabolism is when a person intake sugar or any other food component in the body it gets broken down into simpler molecules by chemical reactions that further leads to the formation of energy used for formation of proteins, carbohydrates, fats etc. inside the body. Anabolism This is the constructive part of metabolism where cellular processes lead to the formation of complex molecules. Basically, anabolism is a formation process that involves three steps that are the production of precursors, reaction or activation of precursors to use energy and assembly of activated precursors to form complex molecules. Protein translation is an anabolic process example that occurs in living cell when amino acids combine to form protein in the presence of energy (Alberts et al. 2013). Catabolism Catabolism is destructive cellular reaction where biomolecules are broken down into simpler or smaller molecules with a release of energy that is further utilized in anabolic processes. Basically, it is an energy formation process where complex molecules get destroyed to release energy. Cellular respiration is purely a catabolic process where biomolecules of digestion are further broken down into smaller molecules to release energy in the form of ATP (DeBerardinis and Thompson, 2012). Discuss the importance of enzymes in the human body The diagram represents an enzyme-substrate complex formation at active site region of the enzyme where the specific substrate molecule binds to undergo a chemical reaction. This diagram is basically the Lock Key Model of Emil Fischers based on lock key hypothesis explaining that active site works as a code for a specific substrate in chemical reaction similarly like every lock persist a specific shape code for the single key. This lock and key model clearly explain the enzymatic specificity for a particular substrate that leads to specific reaction. This process explains the basis of the enzymatic identification by its substrate that leads to a specific reaction in all living processes (Vogt and Di Cera, 2012). Explain the movement of substances in and out of the cell through passive and active transport 5.1 Define `Passive` and `Active` transport. Explain in detail how the following substances move through the plasma membrane stating whether it is an active or passive transport process; - oxygen and carbon dioxide, removal of waste in the kidneys, movement of sodium ions into a nerve cell and phagocytosis Active and passive transport are biological processes that involve the movement of substances inside and outside the cellular body. The active process needs chemical energy for transportation whereas passive transport occurs without the use of chemical energy. In passive transport process, the movement occurs on the basis of concentration level where substance moves from the region of their higher concentration to lower concentration (Kotyk, 2012). Oxygen and Carbon-di-oxide Oxygen and Carbon-di-oxide get diffused inside and outside the cell by a process of osmosis trying to maintain concentration gradient. Therefore, it is a passive transportation process as no energy is utilized in transportation. Removal of waste in the kidney Removal of waste from the blood at glomerulus of the nephron in the kidney is a passive transport process that occurs due to diffusion of waste from their higher concentration to lower concentration. Whereas, in reabsorption process in kidney the useful substances like glucose, vitamins etc. are removed by active transportation in the loop of Henle and convoluted region of the kidney. Movement of sodium ions in nerve cell The movement of sodium ions in nerve cells is an active transport process that requires energy in the form of ATP to cross the plasma membrane of nerve cells. Phagocytosis Phagocytosis is the vascular induction of solid particles inside the cell through identification by specific receptors. This process is an energy dependant process for signal activation therefore; it is active transportation (Wilson, 2012). A sailor is lost at sea; he drank sea water and died the next day. When his body was recovered, paramedics said he would have survived if he had not drunk the sea water; explain why the sea water killed him? The human body has a certain limit of capacity to handle the salt concentration. The plasma membranes are semipermeable structures and high concentration of salt in water if enter the cell and blood stream it leads to fatal effect. In this particular case, high salt concentration due to drinking seas water resulted in the death of sailor (Wilson, 2012). Discuss the importance and use of adenosine triphosphate (ATP) in the human body The sprinter will experience fatigue earlier than marathon because of the insufficient intramuscular ATP concentration. Every individual has the capacity to generate power output in the body. The fall of ATP concentration below 70% leads to fatigue in high-pressure exercises. Marathon usually has a practice of running, therefore, their body develops a potential form of energy whereas sprinter usually does not perform running, therefore, will easily feel fatigue (Buchanan, 2010). References Books Alberts, B., Bray, D., Hopkin, K., Johnson, A., Lewis, J., Raff, M., Roberts, K. and Walter, P., 2013.Essential cell biology. Garland Science. Buchanan, M., 2010.Networks in cell biology. Cambridge University Press. 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