Cell Structure and Photosynthesis

Cell Structure

• Cell Membrane:
  • A thin, semi-permeable membrane that surrounds the cell
  • Regulates what enters and leaves the cell
  • Composed of phospholipid bilayer with proteins embedded
• Cell Wall:
  • Found in plant cells, provides support and protection
  • Made of cellulose, a complex carbohydrate
• Cytoplasm:
  • Jelly-like substance inside the cell membrane
  • Site of many metabolic reactions
• Nucleus:
  • Control center of the cell, contains DNA
  • Surrounded by a double membrane called the nuclear envelope
• Mitochondria:
  • Site of cellular respiration, generates energy for the cell
  • Has inner and outer membranes
• Ribosomes:
  • Site of protein synthesis
  • Found in cytoplasm, attached to endoplasmic reticulum or floating freely
• Endoplasmic Reticulum (ER):
  • Network of membranous tubules and cisternae
  • Involved in protein synthesis, transport, and storage
• Lysosomes:
  • Membrane-bound sacs containing digestive enzymes
  • Break down and recycle cellular waste and foreign substances

Photosynthesis

• Light-Dependent Reactions:
  • Occur in the thylakoid membranes of the chloroplast
  • Light energy is absorbed, converting water into ATP and NADPH
• Light-Independent Reactions (Calvin Cycle):
  • Occur in the stroma of the chloroplast
  • CO2 is fixed into glucose using ATP and NADPH from the light-dependent reactions
• Chloroplast:
  • Organelle found in plant cells, responsible for photosynthesis
  • Contains the pigment chlorophyll, which absorbs light energy
• Chlorophyll:
  • A green pigment that absorbs light energy
  • Found in the thylakoid membranes of the chloroplast
• Factors Affecting Photosynthesis:
  • Light intensity, temperature, CO2 concentration, and water availability all impact the rate of photosynthesis

Test your knowledge of cell structure, including the cell membrane, cell wall, and organelles, as well as the process of photosynthesis, including light-dependent and light-independent reactions.