Biology Notes

Photosynthesis

  • Photosynthesis is a process that turns light energy into food for the plant.
  • Inputs:
    • Taken in by the leaves from the air.
    • Taken in by the roots and moves up through the stem.
  • Process:
    • Light is absorbed by chlorophyll in the leaves.
  • Outputs:
    • Food is made and used by the plant.
      • If the plant doesn't need it right away, it is stored.
    • Oxygen is released from the leaves into the air.

Cell Organelles

  • Nucleus: The organelle that acts as the control center or "brain" of the cell.
  • Cell Wall: Supports and protects plant cells.
  • Cell Membrane: A barrier.
  • Ribosomes: The organelle that produces proteins for the cell.
  • Endoplasmic Reticulum: The organelle that acts as a highway to move proteins around the cell.
  • Vacuole: The organelle that acts as a storage center for the cell.
  • Cytoplasm: The gel-like fluid within a cell that aids in organelle movement and gives the cell structure.
  • Lysosomes: The organelle that aids the cell in eliminating waste and recycling materials within the cell.
  • Chloroplasts: The organelle that takes in sunlight and uses it for photosynthesis to give the cell energy.

Cell Types

Prokaryotic Cells

  • Less complex and smaller than eukaryotic cells.
  • Circular DNA is not enclosed in a nuclear membrane.
  • No nucleus.
  • Uses ribosomes to make proteins.
  • Has cytoplasm.
  • Bound by a cell membrane that helps it maintain homeostasis.
  • Uses some type of cellular respiration to make ATP energy.
  • Example: Bacteria

Eukaryotic Cells

  • More complex and larger than prokaryotic cells.
  • DNA is confined to the nucleus.
  • Has membrane-bound organelles, such as chloroplasts, mitochondria, and endoplasmic reticulum.
  • Examples include animal cells, plant cells, fungus cells, and protist cells.

Shared Features:

  • Both cell types use ribosomes to make proteins.
  • Both cell types have cytoplasm.
  • Both cell types are bound by a cell membrane that helps it maintain homeostasis.
  • Both cell types uses some type of cellular respiration to make ATP energy.

Biomolecules

Carbohydrates

  • Monomer: Monosaccharide
  • Polymer: Polysaccharide
  • Types/Examples: Glucose, fructose, starch, glycogen, chitin, cellulose
  • Common Functions: Quick energy for the cell
  • Structure: Glucose

Proteins

  • Monomer: Amino acids
  • Polymer: Polypeptides
  • Types/Examples: Enzymes, antibodies, hemoglobin, muscle fibers, and most hormones
  • Common Functions: Aid in cellular communication, catalyze reactions, aid in muscle movement, aid in immunity, aid in cell membrane transport
  • Structure: Amino acid

Nucleic Acids

  • Monomer: Nucleotide
  • Polymer: Polynucleotide strand
  • Types/Examples: DNA and RNA
  • Common Functions: Contains genetic information (genetic code)
  • Structure: Nucleotide

Lipids

  • Lipids are NOT polymer molecules and therefore are not made of monomer subunits.
  • Types/Examples: Phospholipids, triglycerides, steroids
  • Common Functions: Long-term energy storage, thermal insulation, main component of cell membranes
  • Structure: Glycerol and Fatty acids