Lab Week 2: Microscope, Cell Structure, Cell Cycle, and Cell Mitosis Review

Flashcards covering key vocabulary related to microscope parts and terminology, cell structure and organelles, and the stages of the cell cycle and mitosis, based on the provided lecture notes.

Coarse adjustment knob

Moves specimen into view; used for initial, rough focusing under a microscope.

Fine adjustment knob

Focuses the specimen for sharp, clear images under a microscope.

Rotating nosepiece

The revolving part of the microscope that holds and changes the objective lenses.

Ocular (Eyepiece)

The lens through which one views the specimen under a microscope, typically providing 10X magnification.

Objective Lenses

Lenses located close to the specimen on a microscope, providing different magnifications (e.g., 4X, 10X, 40X, 100X).

Iris diaphragm

Adjusts the illumination or amount of light reaching the specimen on a microscope.

Condenser

A microscope component that concentrates light onto the specimen.

Rheostat

Regulates the intensity of the light source on a microscope.

Total Magnification

Calculated by multiplying the ocular (eyepiece) magnification by the objective lens magnification.

Parfocal

Describes a microscope feature where a specimen in focus under a low magnification lens remains nearly in focus under a higher magnification lens.

Working Distance

The distance between the objective lens and the slide, which decreases with increased magnification.

Resolution

The ability of a microscope to discriminate two close objects as separate, allowing them to be seen as distinct.

Field of View

The lighted circular area seen through the ocular of a microscope, which decreases with higher magnification lenses.

Plasma Membrane

A double layer of lipids with embedded proteins that serves as an external cell barrier, controls substance transport, maintains electrochemical gradients, and facilitates cell communication.

Cytoplasm

The cellular region between the nuclear and plasma membranes, consisting of fluid cytosol, organelles, and inclusions.

Mitochondria

Rod-like, double-membrane structures with inner cristae, known as the powerhouse of the cell and the site of ATP synthesis.

Ribosomes

Dense particles (rRNA and protein) that are the sites of protein synthesis; found free or attached to the rough endoplasmic reticulum.

Rough Endoplasmic Reticulum (RER)

A membranous system studded with ribosomes, involved in protein synthesis, modification, and packaging, as well as phospholipid synthesis.

Smooth Endoplasmic Reticulum (SER)

A membranous system of sacs and tubules lacking ribosomes, involved in lipid and steroid synthesis, lipid metabolism, and drug detoxification.

Golgi apparatus

A stack of flattened membranes and associated vesicles near the nucleus that packages, modifies, and segregates proteins for secretion, lysosomes, or plasma membrane incorporation.

Peroxisomes

Membranous sacs containing catalase and oxidase enzymes that detoxify substances and break down hydrogen peroxide.

Lysosomes

Membranous sacs containing acid hydrolases, responsible for intracellular digestion.

Microtubules

Cylindrical structures made of tubulin proteins that provide cell support and shape, facilitate intracellular and cellular movements, and form centrioles, cilia, and flagella.

Intermediate Filaments

Tough, insoluble protein fibers that are stable cytoskeletal elements, resisting mechanical forces on the cell.

Microfilaments

Fine filaments composed of actin protein, involved in muscle contraction, other intracellular movements, and forming part of the cell's cytoskeleton.

Centrioles

Paired cylindrical bodies, each composed of nine triplets of microtubules, that organize the microtubule network during mitosis and form the bases of cilia and flagella.

Inclusions

Varied stored substances within the cell (e.g., lipid droplets, glycogen granules, pigment granules) for nutrients, wastes, and cell products.

Cilia

Short, hair-like cell-surface projections composed of microtubules, whose coordinated movement propels substances across cell surfaces.

Flagellum

A long, whip-like cell projection (like a cilium but longer) that propels the cell, such as a sperm tail.

Microvilli

Tubular extensions of the plasma membrane containing actin filaments, designed to increase surface area for absorption.

Nucleus

The largest organelle, enclosed by the nuclear envelope, containing genetic information (DNA) and controlling cell activities.

Nuclear Envelope

A double-membrane structure pierced by pores that surrounds the nucleus, separating nucleoplasm from cytoplasm and regulating substance passage.

Nucleolus

A dense, spherical, non-membrane-bounded body within the nucleus, composed of ribosomal RNA and proteins, which is the site of ribosome subunit manufacture.

Chromatin

Granular, thread-like material composed of DNA and histone proteins within the nucleus, where DNA constitutes the genes.

Cell Cycle

The series of changes a cell undergoes from the time it forms until it divides into two daughter cells.

Interphase

The phase between cell divisions where the cell grows, performs its normal metabolic activities, and prepares for division by replicating DNA and organelles.

G1 Phase

The first gap phase of interphase, characterized by cell growth and routine metabolism.

S Phase

The synthesis phase of interphase, during which DNA replication occurs, resulting in duplicated chromosomes (sister chromatids).

G2 Phase

The second gap phase of interphase, involving further growth and final preparations for cell division.

Restriction Checkpoint

A critical point in the G1 phase where a cell commits to proceeding with division or entering a non-dividing (G0) state.

Mitosis

The process of nuclear division, resulting in two genetically identical nuclei, consisting of prophase, metaphase, anaphase, and telophase.

Cytokinesis

The division of the cytoplasm and its contents following nuclear division (mitosis), resulting in two separate daughter cells.

Prophase

The first stage of mitosis where chromatin condenses into visible chromosomes, the nuclear envelope and nucleolus disperse, and the mitotic spindle begins to form.

Metaphase

The second stage of mitosis where condensed chromosomes align along the metaphase plate (equator) in the middle of the cell.

Anaphase

The third stage of mitosis where sister chromatids separate and move towards opposite poles of the cell, and cytokinesis usually begins.

Telophase

The final stage of mitosis where chromosomes arrive at the poles, decondense, new nuclear envelopes form around the separated chromosomes, and the mitotic spindle disassembles.

Cleavage Furrow

A shallow indentation in the cell surface during cytokinesis, indicating where the cell membrane is pinching inward to divide the cell.