Cell Biology and Microscopy Flashcards

Vocabulary and concept flashcards covering cell structures, organelles, microscopy calculations, and comparisons between prokaryotes, eukaryotes, and viruses based on the lecture material.

Millimeter, Micrometre, and Nanometre relative to $1\,cm$

$$1\,cm = 10\,mm = 10,000\,\mu m = 10,000,000\,nm$$

Actual Size Equation

$$\text{Actual Size} = \frac{\text{Image Size}}{\text{Magnification}}$$

Electron Microscope Resolution

Electron microscopes have better resolution because the wavelength of an electron is shorter than the wavelength of light.

Nuclear Envelope

A double membrane surrounding the nucleus containing nuclear pores that enable the movement of molecules into and out of the nucleus.

Nucleolus

A region within the nucleus that synthesises ribosomes.

Chromatin

The form in which genetic material is usually found within the nucleus.

Functions of the Nucleus

To store genetic material (DNA), synthesise ribosomes, and regulate the production of messenger RNA for protein synthesis.

Cell Surface Membrane

A selectively permeable boundary between the cytoplasm and the outside environment that controls substance movement and contains proteins for cell signalling and recognition.

Rough Endoplasmic Reticulum (RER)

A system of membranes spreading extensively throughout the cell containing ribosomes on its surface for protein synthesis and transport.

Smooth Endoplasmic Reticulum (SER)

An endoplasmic reticulum that differs from the RER because it does not have ribosomes on its outer surface.

Mitochondria Structure

Oval-shaped, double membrane-bound organelles where the inner membrane is folded into cristae; they contain a fluid called matrix, circular DNA, and $70S$ ribosomes.

ATP Production Site

Mitochondria, where aerobic respiration occurs to produce $ATP$ for energy-requiring processes.

Golgi Body

An organelle responsible for the modification and packaging of proteins and lipids for exocytosis or distribution, and the production of lysosomes.

Lysosomes

Vesicles formed by the Golgi body containing digestive enzymes such as proteases, lipases, and lysozymes.

Functions of Lysosomes

Hydrolysing pathogens in phagocytes, digesting old organelles, and breaking down cells after cell death.

80S Ribosomes

Ribosomes found in eukaryotic cells, specifically in the cytoplasm and on the RER.

70S Ribosomes

Ribosomes found in prokaryotic cells, chloroplasts, and mitochondria.

Ribosome Structure

Composed of two subunits, each made of a ribosomal RNA molecule and a protein.

Centrioles

Structures that replicate during interphase and organise microtubules during mitosis.

Microtubules

Components of the cytoskeleton that give the cell structure and allow for transport within the cell.

Cilium

A hair-like structure projecting from a cell that may be motile or non-motile.

Respiratory Cilia

Cilia on respiratory epithelial cells that waft mucus and pathogens/foreign material upwards and out of the lungs.

Microvilli

Cellular projections that increase the surface area of a cell to improve the efficiency of exchange, such as in intestinal epithelial cells.

Chloroplast Structure

Double membrane-bound organelles containing stroma, grana (stacks of thylakoids), $70S$ ribosomes, and circular DNA.

Cellulose

The main constituent of plant cell walls.

Functions of the Plant Cell Wall

Providing mechanical strength, protecting the cell from osmotic lysis, and regulating the movement of water.

Plasmodesmata

Channels that allow the undisrupted flow of materials via the symplastic route and efficient exchange of substances between plant cells.

Large Permanent Vacuole

A plant cell structure that stores cell sap, maintains turgor pressure, and acts as a temporary food store.

Plant-specific Organelles

A cell wall, chloroplasts, large permanent vacuole and tonoplast, and plasmodesmata.

Prokaryote Size

Small, typically $1-5\,\mu m$ in diameter and usually unicellular.

Prokaryotic DNA

Circular DNA in the form of plasmid rings, not associated with histones.

Peptidoglycan

The material that makes up the cell wall of prokaryotes.

Capsid

The protein coat surrounding the nucleic acids (DNA or RNA) of a virus.

Viruses

Acellular structures that possess no organelles or ribosomes and rely on host cells to synthesise viral components.