Unit 2 Cells

• What are the smallest living units of an organism?

  Cells
• What three things do all cells have in common?

  Cell membrane, cytoplasm, and DNA
• What is the function of the cell membrane?

  It separates the inside of the cell from its environment
• What is cytoplasm?


  A jellylike fluid inside the cell
• What distinguishes eukaryotic cells from prokaryotic cells?

  Eukaryotic cells have a nucleus and membrane-enclosed organelles
• What is the function of the nucleus in a cell?

  It is the control center that contains DNA
• What is chromatin?

  The tangled, spread-out form of DNA found inside the nuclear membrane
• What happens to DNA when a cell is ready to divide?

  DNA condenses into structures known as chromosomes
• What is the nucleolus?

  A structure within the nucleus where ribosomes are made
• What is the role of ribosomes in a cell?

  They synthesize or make proteins
• Where do ribosomes go after leaving the nucleus?

  They float in the cytoplasm or attach to the endoplasmic reticulum
• What is the endoplasmic reticulum (ER)?

  A membrane-enclosed passageway for transporting materials
• What distinguishes rough ER from smooth ER?

  Rough ER has ribosomes attached to it, while smooth ER does not
• What happens to proteins as they move through the Golgi apparatus?


  They are customized into usable forms by folding or adding materials
• What are vacuoles?

  Sacklike structures that store different materials
• What is the function of the central vacuole in plant cells?

  It stores water
• What are lysosomes known for?

  They are garbage collectors that break down damaged cell parts
• What is the function of mitochondria?

  They are the powerhouse of the cell, making ATP during cellular respiration
• How do cells that need more energy relate to mitochondria?

  They have more mitochondria
• What is the cytoskeleton's role in a cell?

  It maintains the cell's shape
• What are microfilaments and microtubules?

  Threadlike structures made of protein and thin hollow tubes in the cytoplasm
• What is the function of chloroplasts in plant cells?

  They are where photosynthesis happens
• Why are chloroplasts green?

  Because they contain chlorophyll
• What is the function of the cell wall in plant cells?

  It shapes, supports, and protects the plant cell
• Do animal cells have a cell wall?

  No, animal cells never have a cell wall
• What are cilia and what is their function?

  Microscopic hairlike projections that help trap inhaled particles and expel them
• What is a flagellum and its function?

  A flagellum is a tail-like structure that helps a cell move
• Which human cell has a flagellum?

  The sperm cell
• What are the key differences between eukaryotic and prokaryotic cells?

  • Eukaryotic cells have a nucleus and membrane-enclosed organelles
  • Prokaryotic cells do not have a nucleus or membrane-enclosed organelles
  • Eukaryotic cells can be multicellular (plants and animals)
  • Prokaryotic cells are always unicellular (e.g., bacteria)
• What are the main organelles found in eukaryotic cells and their functions?

  • Nucleus: Control center containing DNA
  • Ribosomes: Synthesize proteins
  • Endoplasmic Reticulum (ER): Transport materials
  • Rough ER: Has ribosomes
  • Smooth ER: No ribosomes
  • Golgi Apparatus: Modifies and packages proteins
  • Mitochondria: Produce ATP
  • Vacuoles: Store materials
  • Lysosomes: Break down cellular debris
  • Chloroplasts (in plant cells): Conduct photosynthesis
• What are the common features of all cells?

  • All cells have a cell membrane
  • All cells have cytoplasm
  • All cells have genetic material (DNA)
• Thykaloids contain chlorophyll
• There is many thykaloids inside the chloroplast to provide a large surface area to capture maximum light for photosynthesis
• The thylakoids/ Granums are surrounded by a watery solution called stroma
• Exocytosis

  Vessicle fuses with a cell surface membrane and releases its contents

  This could be a protein into the blood to target organs or when getting rid of waste products or toxins (lysosomes)
• Why do sperm cells have lots of mitochondria?

  Because mitochondria are the site of aerobic respiration, producing ATP for energy. Energy is released to allow the sperm cells to swim to the egg
• How do mitochondria contribute to the function of sperm cells?

  Mitochondria produce ATP, which provides energy for sperm cells to swim to the egg.
• Why do white blood cells contain lots of lysosomes?

  Because they engulf pathogens and use lysosomes to hydrolyze them with enzymes.
• What is the role of lysosomes in white blood cells?

  Lysosomes contain enzymes that hydrolyze engulfed pathogens.
• Why do red blood cells not have many organelles?

  To maximize space for transporting oxygen.