1. Introduction (Biochemistry)

Introduction of Biochemistry for B.Sc. Nursing

1. Unit 1 Introduction

2. Biochemistry Bio-chemistry is the study of chemical substances and vital processes occurring in living organisms . It includes the study of chemistry behind biological processes and the synthesis of biologically active molecules. Biochemistry is the application of chemistry to the study of biological processes at the cellular and molecular level. It emerged as a distinct discipline around the beginning of the 20th century when scientists combined chemistry, physiology and biology to investigate the chemistry of living systems by:

3. Biochemistry Studying the structure and behavior of the complex molecules found in biological material and The ways these molecules interact to form cells, tissues and whole organism The name Biochemistry was coined in 1903 by a German chemist named Carl Alexander Neuber (1877-1956). The study of biochemistry involves enzymes, nucleic acids, carbohydrates, sugars, proteins, and lipids.

4. Definition and significance in nursing Nursing encompasses autonomous and collaborative care of individual of all ages, families, group and communities, sick or well and in all settings. Nursing includes the promotion of health, prevention of illness, and the care of ill, disabled and dying people. Advocacy, promotion of safe environment, research, participation in shaping health policy and in patient and health systems management, and education area also key role of nursing.

5. Significance in nursing Biochemistry involves the chemical processes that occur in all living cells and organism. It is crucial to nurses in understanding how the human body functions in both normal and various disease states. The Krebs cycle, for example, is a multi-step biochemical process by which the human body (and many other living organism) produces energy as a part of aerobic metabolism. If BSN programs omitted key fundamentals like this, nurses would have no understanding of how such common things as acute and critical illness, trauma, surgery, cardiac arrest, fever, infection, hyperglycemia, or starvation, for example, affected their patients.

6. Significance in nursing Nursing interventions are based on this understanding. In critical care, for instance, nurses learn how to preserve patients' energy by spreading cares throughout the day and night. How medications work is directly related to biochemistry. Antibiotics, for example, work on the various microorganisms differently. Some antibiotics kill bacteria outright, by making holes in their cell walls. Others keep bacteria from replicating by disrupting intracellular processes. Nurses work as part of patient care teams and closely with families.

7. Significance in nursing Biochemistry is significant to the profession of nursing because the vast majority of nurses' patients are human. Humans are biological organisms living in a rich soup of chemical interactions. Biochemistry is that narrow discipline of chemistry concerned with the processes occurring in living organisms. Basically, a nurse should have some understanding of the mechanisms that might support interventions to help their patients feel better and some insight as to the sort of problems that make them feel worse.

8. Significance in nursing If an infants is always vomiting after giving milk ,she or he probably has galactose intolerance. If an infant is born with jaundice, her or his liver is not fully functional. When color of infants urine turns dark ,probably he/she suffers from an amino acid metabolic disorder. Many such condition thus, can be explained on the basis of bio-chemistry.

9. Cells Basic building blocks of life Smallest living unit of an organism Grow, reproduce, use energy, adapt, respond to their environment Many cannot be seen with the naked eye A cell may be an entire organism or it may be one of billions of cells that make up the organism

10. Cells maybe prokaryotic or eukaryotic Prokaryotes include bacteria & lack a nucleus or membrane-bound structures called organelles Eukaryotes include most other cells & have a nucleus and membrane-bound organelles (plants, fungi, & animals)

11. Cell membrane/Plasma membrane Every cell in the body is enclosed by a cell plasma membrane. The cell membrane separates the material outside the cell, It maintains the integrity of a cell and controls passage of materials into and out of the cell. All materials within a cell must have access to the cell membrane (the cell's boundary) for the needed exchange . The membrane is composed of phospholipid molecules arranged in a bilayer. Embedded in the membrane are proteins.

12. Cell membrane/Plasma membrane The cell membrane keeps the cell together by containing the organelles within it. Cell membranes are selectively-permeable, allowing materials to move both into and outside of the cell. Active and passive transport systems; act as a receptor sites and functions as a carrier molecules, and provides identification markers.

13. Nucleus Found in all eukaryotic cells except in mature phloem sieve tube elements and mature red blood cells of mammals. Almost all cells are mono- nucleate, but bi-nucleate cells (some liver and cartilage cells) and poly-nucleate cells (some white blood cells) also exits. It is bounded by a double membrane (nuclear envelope). The envelope possesses many large pores which permit the passage of large molecules, such as RNA. The cytoplasm- like material within the nucleus is called nucleoplasm.

14. Nucleus It contains chromatin which is made up of coils of DNA bound to proteins. Act as a control center for the activities of a cell The nuclear DNA carries the instructions for the synthesis of proteins It is involved in the production of ribosomes and RNA It is essential for cell division

15. Nucleolus Appears as a rounded, darkly stained structure inside the nucleus. One or more nucleoli may be present in a cell. It stains intensely because of the large amounts of DNA and RNA it contains. During nuclear division nucleoli seem to disappear, but this is because the DNA disperses. They reassemble after nuclear division. making ribosomes

16. Cytoplasm Cytoplasm is a jelly-like substance that is sometimes described as "the cell-matrix". It is the medium for chemical reaction. It holds the organelles in place within the cell. All of the functions for cell expansion, growth and replication are carried out in the cytoplasm of a cell. Within the cytoplasm, materials move by diffusion, a physical process that can work only for short distances. Site for Glycolysis and most of gluconeogenesis; Pentose Phosphate shunt; Fatty acid biosynthesis.

17. Ribosomes It is a small (20nm in diameter) and non-membranous structure It consists of two subunits, one large (called 70S) and one small ( called 80S) These are responsible for the processing of genetic instruction carried by mRNA. Some of the ribosome float free in the cytoplasm, called free ribosome while others are bound to endoplasmic reticulum. it acts as a binding site for protein synthesis

18. Mitochondria "Mitochondria" is a plural term; which is appropriate as these are not found alone. The quantity of mitochondria within cells varies with the type of cell. These are power generator and self-replicating organelles. Both the organelles are surrounded by a double membrane with an intermembrane space. Many folding, filling their inner space. they have two functionally distinct membrane systems, inward folds are called cristae.

19. Mitochondria These are the energy producers within the cell. They generate energy in the form of Adenosine Tri-Phosphate (ATP). Site for Krebs Cycle; Electron transport system and Oxidative Phosphorylation; Fatty acid oxidation; Amino acid catabolism; Interconversion of carbon skeletons.

20. Plastid Semi-autonomous organelles having DNA and double membrane envelope which store or synthesis various types of organic compounds It develops from colorless precursors called protoplastids Depending upon their color, they ae of three main types; Leucoplasts ( Amyloplasts , Elaioplasts and Aleuroplasts )/( Leucos ) Chromoplasts ( Chroma ) Chloroplasts ( Chloros )

21. Endoplasmic reticulum ER is the transport network for molecules. It is present in two forms called Rough endoplasmic reticulum (RER) and smooth endoplasmic reticulum (SER) . "Rough" indicates that there are ribosomes attached to the surfaces of the endoplasmic reticulum. The endoplasmic reticulum is the site for membrane and secretary protein biosynthesis. Site of phospholipid biosynthesis and detoxification reactions takes place.

22. Golgi apparatus It is a cup- shaped organelle located near the nucleus in many types of cells. The apparatus consists of a set of smooth cisternae, which close fluid filled flattened membranous sacs or vesicles. Contains a series of five to eight membrane covered stacks called cisternae Animal cells generally contain between ten and twenty Golgi stacks which are linked to a single complex by tubular connections between cisternae

23. Golgi apparatus Their main function is to process the immature enzymes into functional enzymes and to release them in a closed vesicle. Golgi complex participates in cell wall information, i.e. cell plate, primary and secondary wall formation. They are also concerned with giving rise to primary lysosome. They are believed to play a role in regulation of fluid balance. Golgi complex is supposed to play a role in phospholipid synthesis, lipid absorption etc. The packaging of secretory materials, example- mucin, enzyme, milk lactoprotein, melanin pigment etc., which are to be discharged from the cell.

24. Lysosome These contain hydrolytic enzymes and as a matter of fact these are the lytic bodies functioning as suicidal bags. It has a high acidic medium of pH 5.0 and this acidification depends on ATP- dependent proton pumps. Intracellular digestion- Lysosomes are responsible for the digestion of particulars that are taken into the cell by phagocytosis. Autophagy- During adverse conditions, lysosomes begin to digest its own cell inclusions such as mitochondria and ER. This is called cellular autophagy.

25. Lysosome Aging- Lysosomes are considered as agents of aging, for they produce autolytic that slowly disrupt the intracellular machinery. Autolysis- They perform the function of removing the dead or degenerating cells and this process is known as autolysis. Cell division- Lysosomes may be involved in repressing mitotic division of a cell.

26. Cytoskeletal structures They are extremely minute, fibrous and tubular structures which form the structural framework inside the cell O ccur only in eukaryotic cells M aintains shape of the cell and its extensions, regulates orientation and distribution of the cell organelles T hree types; M icrofilaments , I ntermideate filaments and M icrotubules

27. Cytoskeletal structures Microfilaments: Ultramicroscopic, long, narrow cylindrical rods or protein filaments which occur in eukaryotic plant and animal cells Connected with spindle fibers, ER, chloroplasts, etc.. Association with myosin protein Muscle fibers also represents it Intermediate filaments: Hollo filaments often form a network Four types: Keratin filament ( tonofibrils and skin), Neuro filaments (lattice with axon and dendrons of nerve cells), Glial filaments (astrocytes) and Heterogenous filaments (muscles and connected to nuclear envelope and centriole)

28. Microtubules Cylinders that contain 13 rows of protein called tubulin During cell division microtubules form spindle fibres, that assist the movement of chromosomes They work as conveyer belts inside the cells They move vesicles, granules, organelles like mitochondria, and chromosomes via special attachment proteins Microtubules may work alone, or join with other proteins to form more complex structures M ain constituent of the microtubule is a glycoprotein called Tubulin; α-Tubulin and β -Tubulin.

29. Microvilli "Microvilli" is the plural form; "Microvillus" is the singular form. Microvilli are finger-like projections on the outer-surface of the cell. Not all cells have microvilli. Their function is to increase the surface area of the cell, which is the area through which diffusion of materials both into, and out of, the cell is possible.

30. Vacuoles It is a fluid-filled sac bounded by a single membrane (called tonoplast in plant cell) It contains a solution of mineral salts, sugar, amino acids, wastes and sometimes also pigments, these substance are collectively called ‘cell sap’ Support and cell growth Store pigments As lysosome : sometimes it may contain hydrolytic enzymes, after cell death the tonoplast losses its differential permeability and the enzymes escape causing autolysis

31. Vacuoles Depending upon the contents and functions, vacuoles are of four types: Sap vacuoles (Fluid-filled, maintain cell shape, turgidity and water absorption) Contractile vacuoles (Occurs in some protistan and algal cells, highly extensible and collapsible membrane, osmoregulation and excretion) Food vacuoles (Protozoans protists, several lower animals and phagocytes of higher animals, fusion of phagosome and lysosome, digest material passed out into surrounding cytoplasm) Air vacuoles/pseudo vacuoles/gas vacuoles (prokaryotes, not only store metabolic gases but also provide buoyancy, mechanical strength and protection from harmful radiation)

32. Centrosomes The centrosomes contain the centrioles, which are responsible for cell-division.

33. Biomolecules Just like cells are building blocks of tissues likewise molecules are building blocks of cells Animal and plant cells contain approximately 10, 000 kinds of molecules (bio-molecules) Water constitutes 50-95% of cells content by weight Ions like Na+, K+ and Ca+ may account for another 1% Almost all other kinds of bio-molecules are organic (C, H, N, O, P, S) Infinite variety of molecules contain C Most bio-molecules considered to be derived from hydrocarbons The chemical properties of organic bio-molecules are determined by their functional groups. Most bio-molecules have more than one