[DOST] BIOLOGY

• cell: known as the basic unit of life
• Major Classification of Cell:

  1. Prokaryotic
  2. Eukaryotic
• Prokaryotic Cell

  • lacks a nucleus and organelles that are enclosed within a membrane
  • smaller in size and are mostly unicellular
  • bacteria and archaea
• Eukaryotic Cell

  • contains a nucleus and membrane-bound organelles
  • larger in size and are mostly multicellular
  • fungi, animals, plants
• Which is TRUE about Prokaryotic and Eukaryotic Cells?: Bacteria are prokaryotes while animals and plants are eukaryotes.
• cell membrane: regulates transport of materials entering and exiting the cell
• The cell membrane consists of:

  1. phospholipid bilayer
  2. hydrophilic head
  3. hydrophobic tail
• The cell membrane is amphiphilic.
• Cell membrane demonstrates the fluid mosaic model.
• The membrane is not rigid; its components can move around freely within the layer.
• Cell Transport

  1. Passive Transport
  2. Osmosis
  3. Active Transport
• Passive Transport: allows small molecules to diffuse through the membrane.
• Osmosis: movement of solvent molecules from an area of high concentration to low concentration through a semipermeable membrane.
• Active Transport: required the input of energy (ATP) to transport molecules across a concentration gradient.
• The following are characteristics of the cell membrane EXCEPT for: Passive transport requires ATP to transport molecules along the membrane.
• ATP: Adenosine Triphosphate
• ATP: the energy currency of the cell
• ATP: used to power different metabolic processes of the body.
• Cell Metabolism: upon intake of the food the body breaks it down into smaller molecules for absorption.
• Glycolysis: responsible for the break down of glucose into pyruvate and ATP.
• 1 mol of glucose produces 2 Net ATP, 2 Pyruvate molecules, and 2 NADH
• NADH: Nicotinamide adenine dinucleotide
• Citric Acid Cycle is also known as:

  1. Tricarboxylic acid cycle
  2. Kreb's Cycle
• Citric Acid Cycle: central metabolic pathway
• Citric acid cycle is responsible in harvesting energy from carbon skeletons and producing intermidiates.
• 1 mol of acetyl coa produces 3 NADH, 1 FADH2, 1 ATP
• FADH2: Flavin adenine dinucleotide
• Pentose Phosphate Pathway

  1. series of interconversion of sugars to produce precursors of nucleic acids
  2. regulates cellular redox reactions
• Photosynthesis

  1. occurs in plant cells and some algae.
  2. converts carbon dioxide into oxygen and sugar using sunlight and water
  3. happens in the chloroplast
• Photosynthesis: 6CO2 + 6H2O (chlorophyll → sunlight) C6H12O6 + 6O2
• Glycolysis: This metabolic pathway is responsible for breaking down glucose into ATP and pyruvate.
• Biological Macromolecules: essential organic molecules which are responsible in sustaining different life processes.
• Major Biological Macromolecules:

  1. Carbohydrates
  2. Protein
  3. Lipids
  4. Nucleic Acids
• Carbohydrates

  1. BUILDING BLOCKS: monosaccharides (ex. glucose)
  2. provides energy to the cell (source of food, supports cell structure)
  3. bread, sugar, starch
• Proteins

  1. BUILDING BLOCKS: amino acids
  2. provide cell structure and constitutes enzyme for chemical reactions
  3. animal-based foods, fish, beef, chicken, dairy
• Lipids

  1. BUILDING BLOCKS: fatty acids and glycerol
  2. provide structural support, cellular signaling, and energy storage
  3. fats and oils
• Nucleic acids

  1. BUILDING BLOCKS: nucleotides
  2. store genetic information in living organisms
  3. DNA and RNA
• Which of the following biological macromolecules corresponds correctly to its monomer?: carbohydrate - monossacharide
• Cell Cycle

  • G1 Phase: cell increases in size
  • S Phase: DNA duplicates
  • G2 Phase: cell prepares for division
  • Cell division (Mitosis: Prophase, Metaphase, Anaphase, Telophase)
• Mitosis

  • produces two daughter cells which contain the same chromosome as the parent
  • cell growth, development, and replacement