Chapter 1: Cell Structure Flashcards
Magnification Calculation
Magnification = Image Size / Actual Size.
Eyepiece Graticule
An eyepiece graticule is used with a stage micrometer to make precise measurements in microscopy, using units such as mm, µm, and nm.
Resolution
Resolution is the ability to distinguish two close objects as separate. It is higher in electron microscopy compared to light microscopy.
Magnification
Magnification is the ratio of the size of the image to the actual size of the specimen.
Cell Surface Membrane
A selectively permeable barrier surrounding the cell, controlling the entry and exit of substances.
Nucleus
Contains the genetic material (DNA) and is the control center for cell activities.
Nuclear Envelope
A double membrane surrounding the nucleus, containing pores for transport.
Nucleolus
A dense region within the nucleus where ribosome synthesis occurs.
Rough Endoplasmic Reticulum (RER)
Studded with ribosomes; involved in protein synthesis and modification.
Smooth Endoplasmic Reticulum (SER)
Lacks ribosomes; involved in lipid synthesis and detoxification.
Golgi Body
Involved in the modification, sorting, and packaging of proteins and lipids for secretion.
Mitochondria
Powerhouse of the cell; site of ATP production and contains small circular DNA.
Ribosomes
Sites of protein synthesis; 80S in the cytoplasm, 70S in chloroplasts and mitochondria.
Lysosomes
Organelles containing digestive enzymes for breaking down waste materials.
Centrioles
Involved in cell division and the organization of microtubules.
Microtubules
Cytoskeletal components that provide structural support and transport within cells.
Cilia
Hair-like structures that aid in movement and the transport of substances across the cell surface.
Microvilli
Small finger-like projections that increase surface area for absorption.
Chloroplasts
Site of photosynthesis in plant cells; contains small circular DNA.
Cell Wall
Rigid outer layer of plant cells providing structure and support.
Plasmodesmata
Microscopic channels in the cell wall allowing transport and communication between plant cells.
Large Permanent Vacuole
Storage organelle in plant cells, maintaining turgor pressure; surrounded by tonoplast.
ATP
Adenosine triphosphate; energy currency of the cell used for energy-requiring processes.
Prokaryotic Cell
Unicellular organisms that lack a nucleus and membrane-bound organelles; generally 1–5 µm in diameter.
Peptidoglycan Cell Walls
Structural component of prokaryotic cell walls, providing rigidity.
Circular DNA
DNA structure found in prokaryotic cells, allowing for replication and gene expression.
Ribosomes in prokaryotic vs eukaryotic
70S Ribosomes found in prokaryotic cells; smaller than eukaryotic ribosomes (80S).
Non-cellular Viruses
Structures with a nucleic acid core (DNA or RNA) and a protein capsid; may have a phospholipid envelope.
