Nucleic Acids Life Maintainers

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Nucleic AcidsLife Maintainers

• Monomer Nucleotide
• Information storage e.g., Deoxyribo Nucleic Acid
  (DNA)
• Synthesis of Proteins e.g., Ribo Nucleic Acid
  (RNA)
• Energy e.g., ATP, NAD

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Organization of life
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Cells

• Smallest functional living unit
• Factory running lives
• Plasma Membrane The Security guard
• Nucleus The Managing Director
• Carrier molecules (Receptors) Receptionists
• Mitochondrion Stockists
• Endoplasmic Reticulum Personal Assistants
• Golgi bodies Quality control engineer
• Lysosomes Janitors

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Tissues
Organs

• Epithelial (Skin)
• Connective (blood)
• Muscular (smooth muscles)
• Nervous (nerves)

• Heart
• Brain
• Lungs
• Liver
• Kidney

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Homeostasis

• Ability to maintain a relatively constant
  internal environment
• Description of physical and chemical parameters
  that an organism must maintain to allow proper
  functioning of its component cells, tissues,
  organs, and organ systems
• Humans Regulators
• Maintain internal stability
• Changes corresponding to external environment
• Operated mainly by nervous and endocrine systems

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Internal human environment

• 2 types of extracellular fluids
• extracellular fluid that surrounds and bathes
  cells
• plasma, the liquid component of the blood

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• Internal components of homeostasis
• Concentration of oxygen and carbon dioxide
• pH of the internal environment
• Concentration of nutrients and waste products
• Concentration of salt and other electrolytes
• Volume and pressure of extracellular fluid

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Control Systems
Extrinsic (controlled from outside the body)
Intrinsic (Local, involves only single cell or
organ)
Feedback Systems
Negative Feedback (information caused by the
feedback causes a reverse of the response )
Positive Feedback (amplifies the response)
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Examples of Homeostatic changes

• Thermoregulation (maintains _at_ 37C)
• Sweat, shivering etc.
• Osmoregulation (maintains pH 7)
• ADH/Urination
• Glucoregulation (maintains sugar level between
  100-120 mg/dl)
• Insulin/glucagon balance

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Life Processes

• Metabolism
• Digestion
• Assimilation
• Absorption
• Excretion
• Circulation

• Respiration
• Movement
• Reproduction
• Growth
• Differentiation
• Responsiveness

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Activity of Life

• Metabolism
• Sum of chemical changes that convert nutrients
  into energy and finally to complex finished
  products of cells
• Process through which organisms acquire and
  utilize energy for their function

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Metabolism

• Catabolism
• Degradative pathways
• Usually energy- yielding!

Anabolism

• Biosynthetic pathways
• Usually energy-requiring!

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Membrane transport
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Diffusion

• The movement of molecules from high concentration
  of Solutes to low concentration of Solutes
• Or from region with greater volume of water to
  region with lesser volume

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Osmosis

• Diffusion across semi-permeable membrane
• Selectively permeable - only allowing certain
  substances to pass through
• e.g. window screen, greenhouse ..

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Regulation of Membrane Transport/Signaling

• Membranes can regulate passage of substances
  through transporters (protein)
• Carriers molecules are required for facilitated
  transport and active transport