Voice of the Genome

• What are all living organisms made of?

  Cells
• How are cells organized in multicellular organisms?

  Cells into tissues, tissues into organs
• What type of cells are humans made up of?

  Eukaryotic cells
• What do eukaryotic cells contain?

  A nucleus and membrane-bound organelles
• What can be observed using a microscope?

  Ultrastructure of a cell
• What is the ultrastructure of eukaryotic cells?

  • Nucleus: double membrane, contains DNA and nucleolus
  • Rough Endoplasmic Reticulum: folds and processes proteins
  • Smooth Endoplasmic Reticulum: produces and processes lipids
  • Golgi Apparatus: modifies and packages proteins and lipids
  • Mitochondria: site of cellular respiration
  • Centrioles: involved in cell division
  • Ribosomes: site of protein synthesis
  • Lysosomes: contain digestive enzymes
• What surrounds the nucleus?

  A double membrane called the envelope
• What is the function of the nucleolus?

  Site of ribosome production
• What is the structure of Rough Endoplasmic Reticulum?

  Flattened sacs with ribosomes on the surface
• What does the Rough Endoplasmic Reticulum do?

  Folds and processes proteins
• What does the Smooth Endoplasmic Reticulum produce?

  Lipids
• What is the Golgi Apparatus's role?

  Modifies and packages proteins and lipids
• What is the shape of mitochondria?

  Usually oval shaped
• What is contained in the fluid matrix of mitochondria?

  Enzymes needed for cellular respiration
• What are centrioles made of?

  Microtubules arranged in a ring
• What is the function of centrioles?

  Involved in cell division
• What type of ribosomes do eukaryotic cells have?

  80S ribosomes
• What do lysosomes contain?

  Digestive enzymes
• Where are proteins produced?

  On the ribosomes
• What happens to proteins produced on ribosomes on the RER?

  They are folded and processed in the RER
• How are proteins transported from the RER to the Golgi apparatus?

  In vesicles
• What modification occurs to proteins in the Golgi apparatus?

  Carbohydrates are added to form glycoproteins
• What does the Golgi apparatus do with proteins?

  Packages proteins into vesicles
• How do some proteins leave the cell?

  By exocytosis
• What is the ultrastructure of prokaryotic cells?

  • Cell Wall: rigid outer covering made of peptidoglycan
  • Slime Capsule: protective layer for moisture retention
  • Plasmid: circular pieces of DNA
  • Flagellum: tail-like structure for movement
  • Pili: hair-like structures for attachment
  • 70S Ribosomes: site of protein synthesis
  • Mesosomes: debated function, possibly for respiration

  
• What is the cell wall made of in prokaryotic cells?

  Peptidoglycan
• What is the function of the slime capsule?

  Helps retain moisture and adhere to surfaces
• What are plasmids?

  Circular pieces of DNA
• What is the function of the flagellum?

  Rotates to move the cell
• What are pili used for?

  Attachment to other bacterial cells
• What type of ribosomes do prokaryotic cells have?

  70S ribosomes
• What are mesosomes believed to contain?

  Enzymes required for respiration
• What are the key features of mammalian gametes?

  Ovum:

  • Zona pellucida: protective coating
  • Haploid nucleus: restores chromosome set
  • Cortical granules: harden zona pellucida
  • Follicle cells: protective coating

  
  

  Spermatozoa:

  • Many mitochondria: energy for movement
  • Acrosomes: contain enzymes to penetrate egg

  
• What is the zona pellucida?

  A protective coating around the ovum
• What is the main purpose of the zona pellucida?

  To prevent polyspermy
• What type of nucleus does the ovum contain?

  A haploid nucleus

  
• What do cortical granules do?

  Cause the zona pellucida to harden
• What do sperm cells contain many of?

  Mitochondria
• What is the function of the acrosome in sperm cells?

  Contains enzymes to break down zona pellucida
• What are the steps of fertilisation?

  1. Sperm head meets zona pellucida; acrosome reaction occurs.
  2. Sperm head fuses with egg cell membrane.
  3. Cortical reaction hardens zona pellucida.
  4. Nuclei fuse, restoring diploid zygote.