Cell Theory

w

What are the light features of a light compound microscope?

Image reversal, Total magnification and resolving power.total magnification,

How many times does the ocular magnify?

10x

What is the third phenomenon of the microscope?

Resolving power—better resolution

What is the first type of electron microscope?

Scanning Electron Mircoscope(SEM)

What is the difference between the light microscope and the electron microscope?

The light microscope uses visible light to illuminate specimens, whereas the electron microscope uses a beam of electrons for higher resolution and magnification.

What is the disadvantage of using the electron microscopes?

Cannot be used to observe live organisms; they need to be dehydrated.

What can a transmission electron microscope be used for?

to study inside of a cell

What is an “Other” microscope?

Dissecting microscope

What two microscopes are in schools?

Light and dissecting microscopes.

Light Compound Microscope

A microscope that provides high magnification, high resolution, and the ability to observe live specimens, but mainly uses slides and can only observe small live specimens (rarely).

Electron Microscope

A microscope providing the highest magnification and highest resolution, producing either a 3D image (SEM) or cross-section (TEM), but restricted to observing dehydrated (dead) specimens.

SEM

Scanning Electron Microscope; an electron microscope technique that produces a 3D image of a specimen.

TEM

Transmission Electron Microscope; an electron microscope technique that produces a cross-section image of a specimen.

Dissecting Microscope

A microscope that provides a 3D image and can observe larger live specimens than a light compound microscope, but features the lowest magnification and lower resolution.

What are the small pieces inside the cell?

organelles

Define any of the organelles, or give a general function or general definition of an organelle,

Any structure within the cell that has a specific job.

Major cell organelles

A group of key cellular structures that includes the nucleus, central vacuole, mitochondrion, and chloroplast.

Nucleus

Identified as one of the major cell organelles.

Central vacuole

Identified as one of the major cell organelles.

Mitochondrion

Identified as one of the major cell organelles.

Chloroplast

Identified as one of the major cell organelles.

What is another name for DNA genetic material?

Chromatin Fibre

Chloroplasts

Organelles that use energy from the sun to turn carbon dioxide and water into glucose through the process of photosynthesis.

Photosynthesis

The process through which chloroplasts use light energy to convert carbon dioxide ($6\,CO_2$) and water ($6\,H_2O$) into glucose ($C_6H_{12}O_6$) and oxygen gas ($6\,O_2$).

Mitochondria

Organelles that turn food energy (glucose) into chemical energy (ATP) through the process of cellular respiration.

Cellular Respiration

The process through which mitochondria turn food energy (glucose, $C_6H_{12}O_6$) and oxygen gas ($6\,O_2$) into carbon dioxide ($6\,CO_2$), water ($6\,H_2O$), and chemical energy (ATP).

ATP

Chemical energy produced by mitochondria from food energy (glucose) through the process of cellular respiration.

Glucose ($C_6H_{12}O_6$)

Food energy produced via photosynthesis in chloroplasts and turned into chemical energy (ATP) by mitochondria during cellular respiration.

Photosynthesis and Cellular Respiration Equations

The summary equations illustrating chloroplasts converting $6\,CO_2 + 6\,H_2O$ with light energy into $C_6H_{12}O_6 + 6\,O_2$, and mitochondria converting $C_6H_{12}O_6 + 6\,O_2$ into $6\,CO_2 + 6\,H_2O + \text{ATPs (Energy)}$.

What is a function of smooth ER?

It stores calcium ions

What is the function of rough ER?

It synthesizes proteins from ribosomes.

What is ER?

The endoplasmic reticulum (ER) is an organelle that plays a critical role in the synthesis and processing of proteins and lipids.

Cell

The basic unit of function and structure of every organism and the fundamental unit of life.

First Tenet of Cell Theory

Formulated between 1838–1839 by Matthias Schleiden and Theodore Schwann, stating that all living things are composed of one or more cells.

Second Tenet of Cell Theory

Proposed in 1855 by Rudolf Virchow, stating that all cells come from pre-existing cells.

Zacharius Janssen

Dutch inventor associated with early microscope developments in 1590 in Holland.

Anton van Leeuwenhoek

Dutch scientist who in 1660 discovered bacteria, protists, sperm cells, blood cells, and nematodes using powerful single-lens magnifying devices.

Leeuwenhoek's Microscope

A single-lens instrument measuring 3-4 inches long with a specimen mounted on a sharp point adjusted by two screws.

Robert Hooke

English scientist who in 1665 observed box-like units in cork tissue, named them "cells", and reported his findings to the Royal Society of London.

Light Compound Microscope

An optical instrument that passes visible light through a specimen and magnifies cellular structures using multiple lenses.

Total Magnification

The overall magnification of a microscope calculated as: $\text{Ocular Lens Power} \times \text{Objective Lens Power}$.

Electron Microscope (EM)

A microscope invented in 1950 that focuses a beam of electrons through or onto a specimen, providing greater resolving power and magnification up to 100,000 times.

Scanning Electron Microscope (SEM)

A type of electron microscope used to examine 3D surface structures of specimens.

Transmission Electron Microscope (TEM)

A type of electron microscope used to study internal cell structures through thin cross-sections or longitudinal sections.

Dissecting Microscope

A optical microscope that provides 3D images and allows observation of larger live specimens, operating at lower magnification and resolution than compound microscopes.

Organelle

Any structure within a cell that performs a specific job or function.

Nucleus

The information center of the cell that controls all cellular activities through DNA messages and contains DNA.

Central Vacuole

A large organelle found in plant cells that functions in storage and structural support.

Mitochondrion

The site of cellular respiration that turns food energy (glucose) into chemical energy ($\text{ATP}$) and possesses an outer membrane and an inner membrane with many folds.

Chloroplast

The site of photosynthesis in plant cells that uses energy from sunlight to turn carbon dioxide and water into glucose.

Ribosomes

The smallest organelles in the cell that are involved in protein synthesis, which can be free-floating in the cytoplasm or bound to membranes.

Endoplasmic Reticulum (ER)

A system of membranes throughout the cytoplasm that is continuous with the nuclear envelope.

Smooth ER

The portion of the endoplasmic reticulum that lacks ribosomes and functions to synthesize lipids, detoxify poisons and drugs, and store calcium.

Rough ER

The portion of the endoplasmic reticulum studded with ribosomes that serves as a membrane factory and synthesizes proteins.

Golgi Apparatus

The shipping and receiving center of the cell that receives transport vesicles from the ER, modifies products of the ER, manufactures certain macromolecules, and ships products to other locations.

Cis Face

The receiving side of the Golgi apparatus.

Trans Face

The shipping side of the Golgi apparatus.

Lysosomes

Organelles containing chemicals and enzymes that digest food materials entering the cell and recycle old organelles and chemical parts.

Centrioles

A pair of structures contained within the centrosome that are made of microtubules and play an important role in cell division.

Cytoplasm

Gel-like material filling the space between the cell membrane and nuclear envelope that contains various organelles.

Plasma Membrane

A semipermeable barrier consisting of two layers of phospholipids and proteins that acts as a selective barrier controlling the passage of nutrients and wastes.

Cell Wall

A rigid layer outside the cell membrane found in plants and bacteria that protects and supports the cell.

Cytoskeleton

A system of microtubules, microfilaments, and intermediate filaments that provides support and motility to the cell.

Extracellular Matrix (ECM)

A structure composed of proteins and carbohydrates that covers animal cells, providing support in place of a cell wall.

Prokaryotic Cells

Smaller, simpler cells that first evolved approximately $3.5\text{ billion years ago}$, lack a nucleus enclosed by a nuclear membrane, lack membrane-bound organelles, and store DNA in a nucleoid region.

Eukaryotic Cells

Larger, more complex cells that first evolved approximately $2.1\text{ billion years ago}$, contain a true nucleus enclosed by a nuclear membrane, and feature membrane-bound organelles.

Nucleoid

The non-membrane-bound region in prokaryotic cells where the single circular chromosome/DNA is concentrated.

Photosynthesis Reaction

The chemical process carried out in chloroplasts, represented as $6CO_2 + 6H_2O \rightarrow C_6H_{12}O_6 + 6O_2$.

Cellular Respiration Reaction

The chemical process carried out in mitochondria, represented as $C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{ATP}$.