Life Sciences: Chemistry of Life (PDF)

**[LIFE SCIENCES ]** **[Chemistry of Life]** **Inorganic compound** -- not living origin, not burn in oxygen and no carbon hydrogen bonds. [Functions of water:] Water (is inorganic) -- 75% of all life consists of water, H and O in 2:1 ratio Regulate body temperature - water lost by sweat , evap...

**[LIFE SCIENCES ]** **[Chemistry of Life]** **Inorganic compound** -- not living origin, not burn in oxygen and no carbon hydrogen bonds. [Functions of water:] Water (is inorganic) -- 75% of all life consists of water, H and O in 2:1 ratio Regulate body temperature - water lost by sweat , evaporates and cools body. Lubricant -- water facilitates chewing and swallowing, helps digestive tract. Medium of chemical reactions- All chemical reactions take place in water. [Functions of minerals:] Minerals- inorganic substances absorbed by (plants , animals humans) Macro elements: mineral salts large quantities. Calcium(Ca) -- strong bones and teeth. rickets and poor growth in plants if there is deficiency. Sodium(Na)- water balance in body, control heart rhythm. Muscle cramp for humans and unknown for plants if there is deficiency. Micro elements- mineral salts in small quantities. Iron(Fe)- Formation of chlorophyll in plants. Transports o2 in blood. Anemia for humans and yellowing of leaves for plants if there is deficiency. Eutrophication -- water has minerals and nutrients. algae overgrowth, aquatic death. **Organic compound** -- Origin from living organisms , large molecule. Carbohydrates -- C,H,O in 1:2:1 ratio, monosaccharide = 1 saccharide , Disaccharide = 2 saccharides, Polysaccharide = 3 or more saccharides. [Function of carbohydrates] Glucose is main energy, cellulose makes cell walls strong. +-----------------+-----------------+-----------------+-----------------+ | | Monosaccharides | Disaccharides | Polysaccharides | +=================+=================+=================+=================+ | Sub units | One | Two | Two or more | +-----------------+-----------------+-----------------+-----------------+ | Main Function | Energy source | Form of | Storage | | | | transport | | +-----------------+-----------------+-----------------+-----------------+ | Examples | Glucose | Lactose | Cellulose | | | | | | | | Galactose | Sucrose | Glycogen | | | | | | | | Fructose | Maltose | Starch | +-----------------+-----------------+-----------------+-----------------+ **[Proteins]** [Properties of Proteins] Composed of C, H, O, N; monomer is amino acid. Amino acids linked by peptide bonds. Sensitive to temperature and pH; denatured under extreme conditions. [Protein Types] (Peptides) Dipeptide: Two amino acids linked by peptide bonds. Tripeptide: Three amino acids linked by peptide bonds. Protein: Over 50 amino acids linked by peptide bonds. Functions of Proteins Structural component in body tissues, e.g., myosin, collagen. Transport molecules, e.g., hemoglobin for oxygen and carbon dioxide. Enzyme formation for metabolism, e.g., digestion reactions. **[Enzymes - General Properties]** Proteins acting as biological catalysts. Lower activation energy; reusable. pH and temperature sensitive; denatured outside optimal range. [How Enzymes Work] - Substrate-specific; forms enzyme-substrate complex. - Lowers activation energy; substrate changes to product. - Enzyme remains unchanged, reusable. [Enzyme Reactions] Anabolic: Builds complex molecules, requires energy. Catabolic: Breaks down molecules, releases energy. Factors Affecting Enzyme Activity - Temperature: Optimal at 35-40˚C, denatures at high temperatures. - pH: Each enzyme has a specific optimal pH range. General Uses of Enzymes - Found in detergents for stain removal (proteins). - Optimal function in water temperature 35-40˚C. **Properties of Lipids** - Contains C, H, O in a 1:2 ratio. - Insoluble in water; soluble in ether, alcohol. - Consists of glycerol and three fatty acids. Types of Lipids: Saturated and Unsaturated - Saturated: Animal-based, solid at room temperature, e.g., butter. - Unsaturated: Plant-based, liquid at room temperature, e.g., oils. Functions of Lipids - Absorb fat-soluble vitamins A, D, E, K. - Shock absorber, e.g., kidney protection. - Insulator and waterproof layer in cells. **Nucleic Acids** - Composed of C, H, O, N, P. - Building block: Nucleotide. - Types: DNA and RNA. DNA (Deoxyribonucleic Acid) - Double helix; carries genetic information. - Located in nucleus; controls cell functions. RNA (Ribonucleic Acid) - Single strand; involved in protein synthesis. - Found in nucleus and cytoplasm, part of ribosomes. Functions of Nucleic Acids - DNA: Genetic blueprint and cellular control. - RNA: Protein synthesis, aligns amino acids. **Vitamins Overview** - Essential for growth, metabolism; produced by plants. - Classified as water-soluble or fat-soluble. Water-Soluble Vitamins (B, C) - Absorbed with water, excreted in urine. - Need regular intake as they\'re not stored. Fat-Soluble Vitamins (A, D, E, K) - Absorbed with fat; stored in body. - Deficiency can lead to diseases, e.g., night blindness for A. **[Introduction to Cells]** - Cells comprise proteins, carbohydrates, lipids, nucleic acids, water. - Main cell parts: nucleus, cytoplasm, cell membrane, organelles. - Types: Prokaryotic (no nucleus) & Eukaryotic (with nucleus). Cell Membrane: Structure - Thin, elastic boundary; selectively permeable. - Phospholipid bilayer with hydrophilic heads and hydrophobic tails. - Contains proteins, glycoproteins, glycolipids for transport and ID. Cell Membrane: Movement - Intracellular (within cells) and intercellular (between cells) movement. - Transport methods: diffusion, osmosis, active transport. Cell Wall (Plants Only) - Non-living, supportive layer outside cell membrane. - Layers: primary wall, middle lamella, secondary wall. - Provides strength, rigidity, and protection. Cytoplasm Structure & Function - Gel and liquid ground plasma; holds organelles. - Site of metabolic processes; stores vital substances. - Aids cell shape maintenance. Nucleus Structure & Function - Includes nuclear membrane, nucleoplasm, nucleolus, chromatin. - Controls cell activities, stores DNA, produces ribosomes. - Nuclear pores facilitate material exchange. Mitochondrion Structure & Function - Double membrane, inner cristae, matrix with ribosomes. - Site of cellular respiration, produces ATP for energy. Ribosomes Structure & Function - Spherical structures in cytoplasm or on ER. - Composed of RNA and proteins. - Site of protein synthesis. Endoplasmic Reticulum (ER) - Network connected to nucleus and cell membrane. - Rough ER (with ribosomes) & Smooth ER (without). - Transports substances within the cell. Golgi Apparatus Structure & Function - Stacks of cisternae with fluid sacs. - Modifies, packages proteins; produces lysosomes. - Transports carbs for cell walls in plants. Vacuole (in Plant Cells) - Large, fluid-filled; surrounded by tonoplast. - Contains cell sap for turgor pressure. - Stores pigments and other substances. Types of Plastids (in Plants) - Chloroplasts: Photosynthesis, contains chlorophyll. - Chromoplasts: Colors flowers, fruits; contains carotenoids. - Leucoplasts: Stores starch, lipids, proteins. Centrosome - Located near nucleus, contains centrioles. - Aids in cell division by organizing microtubules. Similarities: Plant vs. Animal Cells - Both have cell membrane, cytoplasm, ER, Golgi, ribosomes, mitochondria. - Each contains a nucleus with nucleoli and chromatin. Cell Differentiation and Specialization - Process of developing specific cell functions. - Essential for complex organisms; allows specialized cell roles. A screenshot of a computer Description automatically generated **[Mitosis]** [What is Mitosis?] Cell division producing genetically identical cells. Chromosome count remains constant. Occurs in both plant and animal cells. [2. Importance of Mitosis] Essential for growth. Replaces old or damaged cells. Enables asexual reproduction. [3. The Cell Cycle] Mitosis is the final part of the cell cycle. Occurs after the cell has grown and matured. Ensures genetic consistency in daughter cells. [4. Terminology] Cell Division: Process of creating new cells. Chromosomes: Genetic material carriers. Chromatid: Identical DNA strands in a chromosome. Karyokinesis: Division of the nucleus. Cytokinesis: Division of the cytoplasm. [5. Phases of Mitosis] Prophase: Chromosomes condense, nuclear membrane dissolves. Metaphase: Chromosomes align at cell equator. Anaphase: Chromatids pulled to opposite poles. Telophase: New nuclei form, ending mitosis. [6. Interphase] Not part of mitosis; cell spends \~90% of cycle here. DNA replicates and condenses at end. Cell performs regular life activities. [7. Cytokinesis] Final cell division, occurs after telophase. Animal cells: Membrane pinches (cleavage). Plant cells: Cell plate forms new cell walls. 8[. Uncontrolled Mitosis] Faulty stop instruction leads to rapid division. Causes tumors: Benign (harmless) or Malignant (spreading). Tumor cells skip interphase, continuously dividing. [9. Types of Cancer] Carcinoma: Epithelial tissues (lungs, pancreas). Sarcoma: Connective tissues (bone, muscle). Lymphoma: Lymphatic system. Melanoma: Pigment cells in skin. Leukemia: Blood cells. [10. Cancer Causes] Carcinogens: Cigarette smoke, sun, radiation. Chemicals: Asbestos, pollutants. Other: Genetic factors, hormonal imbalances. [11. Cancer Treatments] Early detection improves survival chances. Surgery: Tumor removal. Chemotherapy: Chemical agents kill cancer cells. Radiotherapy: Radioactive radiation targets cancer. **[Plant tissues]** Levels of Organisation Cell: Basic unit of life. Tissue: Similar cells grouped for specific function. Organ: Tissues working together. Organ System: Organs performing collective function. Organism: Whole plant structure. Differentiation Definition: Cells mature and specialize in function. Outcome: Specialized cells form tissues. Meristematic Tissue Apical Meristem: Growth in length; located at tips. Lateral Meristem: Growth in thickness; found in cambium. Permanent Tissue Epidermal Tissue: Protects, allows light; outer layer. Ground Tissue: Parenchyma, sclerenchyma, collenchyma; supports plant. Vascular Tissue: Xylem and phloem; transport system. Epidermal Tissue Structure: Brick-shaped, single-layer, no chloroplasts. Functions: Protects, prevents moisture loss, allows light in. Parenchyma Structure: Large cells, thin walls, chloroplasts. Functions: Stores food, photosynthesis, gaseous exchange. Sclerenchyma Structure: Thick lignin walls, dead cells. Functions: Strengthens, provides rigid support. Collenchyma Structure: Unevenly thickened, flexible cell walls. Functions: Flexible support in young stems, leaves. Vascular Tissue Xylem: Transports water, minerals; strengthens plant. Phloem: Transports nutrients from leaves; living cells. Xylem Structure Vessels: Elongated, lignin-thickened, dead. Tracheid's: Tapered ends, slow water movement. Phloem Structure Sieve Tubes: Elongated, no nucleus, sieve plates. Companion Cells: Perform metabolic functions for sieve tubes. Functions Summary Xylem: Water, mineral transport; structural support. Phloem: Organic nutrient transport to entire plant. **Animal Tissues** 1\. Cell: Basic unit of life. 2\. Tissue: Group of similar specialized cells performing a specific function. 3\. Organ: Group of different tissues working together. 4\. Organ System: Group of organs performing a function. 5\. Organism: The whole body. Differentiation: Cells specialize and form tissues. Types of Animal Tissues: Epithelial Tissues: Characteristics: Cover internal and external surfaces. Tightly packed with no intercellular spaces. Anchored by a basement membrane. [Types:] Squamous: Thin, flat cells (e.g., blood vessels, alveoli). Cuboidal: Cube-shaped cells (e.g., glands, renal tubules). Columnar: Elongated cells (e.g., stomach, intestines). Ciliated Columnar: Columnar cells with cilia (e.g., respiratory tract, fallopian tubes). 2\. [Connective Tissues:] Types: Areolar: Loose connective tissue (beneath skin, around organs). Dense: Dense fibres (tendons, ligaments). Cartilage: Tough, elastic tissue (joints, nose, trachea). Bone: Hard matrix of calcium (bones of skeleton). Blood: Liquid tissue (blood vessels). 3\. Muscle Tissues: Striated: Long, cylindrical cells with light and dark bands (skeletal muscles). Smooth: Spindle-shaped cells (walls of organs, blood vessels). Cardiac: Branched cells connected by intercalated discs (heart). 4\. Nervous Tissues: Neurons: Specialized cells for transmitting impulses. Types: Sensory Neurons: From receptors to CNS. Interneurons: Between sensory and motor neurons in CNS. Motor Neurons: From CNS to effectors (muscles, glands). Functions: Epithelial Tissues: Protection, absorption, secretion, sensation. Connective Tissues: Support, binding, insulation, protection. Muscle Tissues: Movement, contraction, peristalsis, blood flow. Nervous Tissues: Perception, interpretation, response transmission. Immunity Natural (Innate) Immunity First Line of Defence: Skin, coughing, tears, mucus, stomach acid, microbiome. Second Line of Defense: Fever (inhibits pathogen growth) and inflammation (increases blood flow to infection). Acquired (Adaptive) Immunity White Blood Cells: Destroy pathogens using phagocytes, B-lymphocytes (produce antibodies), T-lymphocytes, and memory cells. Types Naturally Acquired: Through natural exposure. Artificially Acquired: Through vaccinations (stimulate immune response and memory). Antibiotics Destroy bacteria, first discovered by Alexander Fleming (Penicillin). [Cloning] Types DNA Cloning: Transfer of DNA segments. Reproductive Cloning: Creating identical organisms (e.g., Dolly the sheep). Therapeutic Cloning: Cloning embryos for stem cell research. Ethical Issues Moral and legal implications, human experimentation concerns.