Microscopy, Cells, and Plant Biology Lecture Notes

Comprehensive practice flashcards covering microscopy history, calculations, cell organelles, membrane transport mechanisms, and plant physiology.

Compound Light Microscope

A microscope first developed in the 1590s with a typical magnification range of $40\times$ to $2400\times$.

Photomicrograph

A typical image of a wet mount or a photograph taken through a microscope.

Dissecting Microscope

A microscope first developed by Robert Hooke in 1665 with a magnification range of $4\times$ to $100\times$.

Ernst Ruska and Max Knoll

The individuals who developed the first electron microscope in 1931.

Transmission Electron Microscope (TEM)

A type of electron microscope that can achieve magnifications of up to $10,000,000\times$.

Scanning Electron Microscope (SEM)

Developed by Manfred Von Ardenne in 1937, it provides magnifications up to $30,000\times$ and shows surface details.

Phase Contrast Microscope

A type of microscope that allows for viewing the inside of living things, such as cells.

Confocal Laser Microscope

A microscope that allows for the viewing of multiple layers of a specimen at the same time.

Total Magnification Formula

$$Total magnification = magnification\,of\,eyepiece \times magnification\,of\,objective\,lens$$

Field of View (FOV)

The area that can be seen when looking through the lens of a microscope; its diameter is measured with a ruler under low power.

Actual Size Formula

$$actual\,size = \frac{FOV\,diameter\,(\mu m)}{fit\,number}$$

Scale Formula

$$Scale = \frac{actual\,size}{drawing\,size}$$

Metabolism

The sum of all chemical reactions in a cell, representing one of the 7 characteristics of life.

Homeostasis

The process of maintaining a stable internal environment.

Prokaryotic Cell

A cell measuring $0.1-10\,\mu m$ that lacks a nucleus and contains a nucleoid region.

Eukaryotic Cell

A cell measuring $10-100\,\mu m$ that contains a nucleus and membrane-bound organelles.

Endosymbiotic Theory

A theory explaining how eukaryotic cells evolved from prokaryotic cells by ingesting aerobic bacteria (which became mitochondria) and cyanobacteria (which became chloroplasts).

Cell Theory

The theory stating all living things are composed of cells, the cell is the basic unit of structure, and all cells come from pre-existing cells.

Plasma Membrane

A selectively permeable phospholipid bilayer composed of proteins and carbohydrates that protects the cell and controls material transport.

Hydrophilic

The 'water loving' head of a lipid in the cell membrane.

Hydrophobic

The 'water hating' tail of a lipid in the cell membrane.

Cytoplasm

A gel-like substance composed mainly of water that contains minerals and creates the chemical environment for cell structures.

Nucleus

The 'control center' of the cell that contains DNA on strands called chromatin and is surrounded by a nuclear envelope.

Nucleolus

A structure inside the nucleus made of proteins and RNA where ribosome synthesis occurs.

Rough Endoplasmic Reticulum

A network of membranous canals lined with ribosomes responsible for protein synthesis, modification, and transport.

Smooth Endoplasmic Reticulum

A network of membranous canals involved in phospholipid synthesis and transport; it contains no ribosomes.

Ribosomes

Small particles that produce proteins by assembling amino acids into chains.

Golgi Apparatus

Stacks of flattened membranous stacks that receive products from the E.R., package them into vesicles, and ship them for transport or secretion.

Peroxisomes

Membrane-bound vesicles containing enzymes that metabolize lipids and detoxify harmful chemicals.

Mitochondria

The 'powerhouse' of the cell where organic molecules are converted into $ATP$ energy through cellular respiration.

Cytoskeleton

A structure including actin filaments, intermediate filaments, and microtubules that maintains cell shape and allows for movement.

Cell Wall

A rigid structure found only in plants that surrounds the cell membrane to protect and support the cell.

Chloroplast

The site of photosynthesis in plant cells where sunlight energy is converted into glucose.

Lysosomes

Organelles found only in animals containing strong digestive enzymes; also known as 'suicide sacs'.

Fluid Mosaic Model

A model stating membranes are composed of a phospholipid bilayer with various protein molecules floating within it.

Passive Transport

The movement of molecules down the concentration gradient without the requirement of energy.

Diffusion

The movement of particles from high to low concentration; used for small uncharged/polar molecules like $O_2$, $CO_2$, and $H_2O$.

Osmosis

The movement of water through a semi-permeable membrane from an area of low solute concentration to high solute concentration.

Hypotonic Solution

A solution that contains a lower concentration of solute than the cell, causing the cell to swell.

Hypertonic Solution

A solution that contains a higher concentration of solute than the cell, causing the cell to shrink.

Facilitated Diffusion

Passive transport using protein channels or carrier proteins for larger uncharged molecules or ions.

Active Transport

The movement of molecules against the concentration gradient requiring energy from the hydrolysis of $ATP$.

Endocytosis

A form of active transport where the membrane folds around a substance to bring it into the cell in a vesicle.

Phagocytosis

A type of endocytosis where cells 'eat' or take in large particles or other cells.

Surface Area to Volume Ratio (SA:V)

A ratio that decreases as a cell grows, eventually limiting the cell's size because the surface area cannot supply enough raw materials for its volume.

Photosynthesis Equation

$$6CO_2 + 6H_2O \rightarrow C_6H_{12}O_6 + 6O_2$$

Cellular Respiration Equation

$$C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{about } 38\,ATP$$

Stomata

Pores in the leaf used for gas exchange, regulated by guard cells.

Transpiration

The process of water vapor evaporating from the leaf through stomata.

Xylem

Plant tissue that conducts water and minerals in a one-way movement; composed of tracheids and vessel elements.

Phloem

Plant tissue that transports water and food in two ways; composed of sieve element cells and companion cells.

Cohesion

The attraction of water molecules to other water molecules.

Adhesion

The attraction of water molecules to molecules of other substances.

Pressure Flow Theory

A theory describing how sugar moves from a source to a sink in the phloem via active transport and osmotic water pressure.

Phototropism

Directional plant growth in response to light, mediated by the molecule auxin.

Gravitropism

Directional plant growth in response to gravity; roots show positive gravitropism while stems show negative gravitropism.