Grade 11 Cell Biology Comprehensive Study Guide

Vocabulary flashcards covering the Grade 11 General Biology 1 Cell Biology Reviewer.

Zoology

The branch of biology studying animals, animal cells, tissues, and physiology.

Botany

The branch of biology studying plants, photosynthesis, and plant cell structures.

Microbiology

The branch of biology studying microscopic organisms such as bacteria and protists.

Genetics

The branch of biology studying heredity, DNA, and gene expression in cells.

Cell Biology

The study of cell structure, organelles, and cellular processes.

Biotechnology

The application of cellular and molecular biology in research and industry.

Homeostasis

The maintenance of stable internal conditions despite environmental changes.

Metabolism

Chemical reactions within cells that convert nutrients to energy and build molecules.

Robert Hooke

English polymath and physicist who observed cork tissue in 1665, coined the term "cells", published Micrographia, and formulated Hooke's Law of Elasticity.

Anton van Leeuwenhoek

Dutch scientist known as the "Father of Microbiology" who observed living "animalcules" in 1674, motile sperm cells in 1677, and bacteria in dental plaque in 1683.

Matthias Schleiden

German botanist who established in 1838 that plants are composed of cells or cell derivatives and referred to the cell nucleus as the cytoblast.

Theodor Schwann

German physiologist who extended cell theory to animals in 1839, isolated pepsin in 1836, coined the term metabolism in 1839, and discovered Schwann cells and the myelin sheath.

Rudolf Virchow

German medical doctor who proposed "Omnis cellula e cellula" in 1855, stating that all cells come from pre-existing cells.

Robert Brown

Scottish botanist who discovered the cell nucleus in orchid cells in 1831 and observed Brownian motion in 1827.

Cytoblast

The term used by Matthias Schleiden to refer to the cell nucleus originally discovered by Robert Brown.

Brownian Motion

The random movement of tiny pollen grains suspended in water observed by Robert Brown in 1827.

Omnis cellula e cellula

Latin phrase proposed by Rudolf Virchow in 1855 meaning that all cells arise only from pre-existing cells.

Prokaryotic Cells

Cells lacking a membrane-bound nucleus and membrane-bound organelles, with DNA located in the nucleoid region, typically ranging from 0.1-5.0\text{ }\text{̲m} in size.

Eukaryotic Cells

Cells containing a true membrane-bound nucleus and membrane-bound organelles, typically ranging from 10-100\text{ }\text{̲m} in size.

Cell Wall

Rigid outer layer in plant cells made mostly of cellulose that provides support, protection, and shape.

Large Central Vacuole

Plant cell organelle storing water, nutrients, ions, and waste, maintaining turgor pressure, and occupying up to about $90\%$ of cell volume.

Centrioles

Paired cylindrical structures consisting of nine triplet microtubules in animal cells that organize cilia, flagella, and the mitotic spindle.

Plasma Membrane

Thin, flexible, selectively permeable barrier controlling what enters and leaves the cell to maintain homeostasis.

Cytoplasm

Gel-like cellular medium (cytosol) that suspends organelles and enables metabolic reactions, transport, and intracellular movement.

Nucleus

Command and control center of the cell that stores DNA and regulates gene expression, metabolism, and cellular activities.

Nucleolus

Dense region within the nucleus that synthesizes ribosomal RNA and assembles ribosome subunits.

Ribosomes

Cellular structures, free or ER-bound, that assemble proteins from amino acids using mRNA templates.

Rough Endoplasmic Reticulum

Membrane network studded with ribosomes that synthesizes, folds, and processes proteins in its lumen.

Smooth Endoplasmic Reticulum

Membrane network lacking ribosomes that synthesizes lipids, detoxifies drugs and poisons, and stores calcium ions.

Golgi Apparatus

Organelle that receives vesicles, modifies proteins and lipids, sorts them, and packages them for delivery or secretion.

Lysosomes

Organelles containing hydrolytic enzymes for intracellular digestion of macromolecules, worn-out organelles, and engulfed particles through autophagy.

Peroxisomes

Organelles containing oxidative enzymes for detoxification, using catalase to convert hydrogen peroxide ($H_2O_2$) into water and oxygen.

Mitochondria

Double-membraned organelles serving as the site of cellular respiration and ATP production, featuring inner membrane cristae and maternal inheritance of mtDNA.

Chloroplasts

Plant organelles containing chlorophyll that capture light energy in thylakoid membranes to carry out photosynthesis and convert $CO_2$ into glucose.

Cytoskeleton

Cellular network composed of microfilaments, intermediate filaments, and microtubules that maintains shape, supports organelles, and enables movement.

Fluid Mosaic Model

Model describing the cell membrane as a dynamic phospholipid bilayer containing proteins, cholesterol, and carbohydrate chains.

Passive Transport

Movement of substances across a cell membrane down concentration gradients without consuming ATP.

Active Transport

Movement of substances across a cell membrane against concentration gradients requiring direct consumption of ATP energy.

Simple Diffusion

Direct passive transport of small nonpolar molecules (such as $O_2$, $CO_2$, and lipids) across the phospholipid bilayer from high to low concentration.

Facilitated Diffusion

Passive transport of polar molecules and ions (such as glucose, amino acids, $Na^+$ and $K^+$) across the membrane via channel or carrier proteins.

Osmosis

Diffusion of water across a selectively permeable membrane from an area of high water potential to low water potential without requiring ATP.

Hypertonic Solution

An environment with higher solute concentration outside the cell, causing water to leave the cell and the cell to shrink.

Isotonic Solution

An environment with equal solute concentration inside and outside the cell, resulting in no net water movement.

Hypotonic Solution

An environment with lower solute concentration outside the cell, causing water to enter the cell so it swells and may undergo lysis.

Sodium-Potassium Pump

Active transport carrier protein that consumes one ATP to pump $3\,Na^+$ ions out of the cell and $2\,K^+$ ions into the cell.

Phagocytosis

Bulk transport mechanism ("cell eating") in which the plasma membrane engulfs large particles or pathogens to form a phagosome for digestion.

Pinocytosis

Bulk transport mechanism ("cell drinking") in which the plasma membrane takes in extracellular fluid and dissolved solutes.

Exocytosis

Bulk transport process in which vesicles fuse with the plasma membrane to release secretory products and waste outside the cell.

Interphase

The major growth and preparation portion of the cell cycle consisting of $G_1$, S, and $G_2$ phases.

S Phase

Phase of interphase where DNA replication occurs, doubling DNA content into identical sister chromatids while maintaining a constant chromosome number.

G0 Phase

A non-dividing state that cells may enter when environmental conditions are unfavorable for cell division.

Cyclins and CDKs

Regulatory proteins that control cell-cycle progression through checkpoints via phosphorylation.

Mitosis

Cellular division process producing two genetically identical daughter cells with equal chromosome distribution for growth, repair, and replacement.

Prophase

First stage of mitosis where chromatin condenses into visible chromosomes, the spindle apparatus forms, and the nuclear envelope breaks down.

Metaphase

Mitotic stage where chromosomes align at the cell equator (metaphase plate) and spindle fibers attach to centromeres.

Anaphase

Mitotic stage where sister chromatids separate and move toward opposite cell poles by shortening spindle microtubules.

Telophase

Final stage of mitosis where nuclear envelopes reform around separated chromosome sets, chromatin decondenses, and the spindle disassembles.

Meiosis

Two-stage cellular division process producing four genetically distinct haploid gametes for sexual reproduction.

Crossing Over

Process during Prophase I of meiosis where homologous chromosomes exchange genetic material to generate genetic diversity.

Independent Assortment

Random alignment of homologous chromosomes at the metaphase plate during Metaphase I of meiosis, creating novel allele combinations.

Proteins

Biological macromolecules built from $20$ different types of amino acids that carry out structural, enzymatic, transport, antibody, and signaling functions.

Lipids

Diverse nonpolar biological molecules (fats, oils, phospholipids, cholesterol) that function in cell membranes, long-term energy storage, insulation, protection, and signaling.

Carbohydrates

Biological sugar molecules broken down into glucose as a primary energy source, excess of which can be stored in the liver and muscles.

Nucleic Acids

Biological macromolecules (DNA and RNA) involved in storing, expressing, and transmitting genomic information in cells.

Benedict's Test

Chemical reagent test using Benedict's solution to identify simple carbohydrates (simple sugars), reacting to simple sugars but not starch.

Iodine Test

Chemical reagent test used to detect the presence of starch.