Cell Biology Reviewer

Flashcards for Cell Biology Review

Cell Biology (Cytology)

The branch of biology that explores the structure and function of the cell, the basic unit of life.

Robert Hooke (1665)

Coined the term 'cell' and observed dead plant cells.

Anton van Leeuwenhoek

Improved the microscope and was the first to observe living cells, including bacteria, sperm cells, and protozoa.

Matthias Schleiden & Theodor Schwann

Proposed the Cell Theory, stating that all living things are composed of cells.

Rudolf Virchow

Added to the Cell Theory by stating 'All cells come from pre-existing cells.'

Principle 1 of Cell Theory

All living organisms are composed of one or more cells.

Principle 2 of Cell Theory

The cell is the basic unit of structure and function in organisms.

Principle 3 of Cell Theory

All cells arise from pre-existing cells.

Prokaryotic Cells

Simple cells without a nucleus or membrane-bound organelles (e.g., bacteria and archaea).

Eukaryotic Cells

Complex cells with a defined nucleus and membrane-bound organelles (e.g., animals, plants, fungi, and protists).

Organelles

Specialized parts within cells responsible for specific functions necessary for cell survival.

Nucleus

The control center of the cell, containing DNA.

Plasma (Cell) Membrane

A semi-permeable membrane that controls what enters and exits the cell.

Cytoplasm

Gel-like substance where organelles are suspended and many biochemical processes occur.

Mitochondria

The 'powerhouse' of the cell, generating ATP through cellular respiration.

Ribosomes

Small structures that synthesize proteins by translating mRNA into amino acid sequences.

Rough Endoplasmic Reticulum (ER)

Involved in protein synthesis and packaging (studded with ribosomes).

Smooth Endoplasmic Reticulum (ER)

Involved in lipid synthesis and detoxification processes (lacks ribosomes).

Golgi Apparatus

Responsible for modifying, sorting, and packaging proteins.

Lysosomes

Contain digestive enzymes to break down waste materials and cellular debris.

Vacuoles

Membrane-bound vesicles used for storing nutrients, waste products, and water.

Chloroplasts

Organelles that carry out photosynthesis, converting sunlight into chemical energy (plant cells only).

Cell Wall

Provides structural support and protection (plant cells only), made primarily of cellulose.

Cellular Respiration

The biochemical process by which cells convert glucose into ATP.

Aerobic Respiration

Requires oxygen and produces about 36-38 ATP molecules per glucose molecule.

Glycolysis

The breakdown of glucose into pyruvate in the cytoplasm.

Krebs Cycle (Citric Acid Cycle)

Pyruvate is converted into Acetyl-CoA, producing electron carriers, ATP, and CO₂.

Electron Transport Chain

High-energy electrons are passed through protein complexes, creating a proton gradient for ATP synthesis.

Anaerobic Respiration (Fermentation)

Does not require oxygen and produces 2 ATP per glucose.

Lactic Acid Fermentation

Pyruvate is converted into lactic acid in muscles when oxygen is scarce.

Alcoholic Fermentation

Pyruvate is converted into ethanol and CO₂ in yeast and some microorganisms.

Hans Krebs

Discovered the Krebs Cycle.

Photosynthesis

The process by which plants convert sunlight into chemical energy (glucose).

Light-Dependent Reactions

Reactions require light and occur in thylakoid membranes in the chloroplasts.

Calvin Cycle / Light-Independent Reactions

ATP and NADPH are used to convert carbon dioxide into glucose in the stroma of the chloroplast.

Jan Ingenhousz

Discovered that light is essential for photosynthesis and the release of oxygen.

Melvin Calvin

Mapped the pathway of carbon fixation in the Calvin Cycle.

Cell Division

Crucial for growth, repair, and reproduction, ensuring cell reproduction and organism maintenance.

Mitosis

Results in two genetically identical daughter cells (somatic cells) for growth, repair, and asexual reproduction.

Prophase

Chromosomes condense, and the nuclear envelope begins to break down.

Metaphase

Chromosomes align at the cell's equator.

Anaphase

Sister chromatids are pulled apart toward opposite poles.

Telophase

Nuclear envelope reforms around the separated chromatids.

Cytokinesis

The cell membrane pinches in to form two daughter cells.

Meiosis

Occurs in germ cells (sperm and egg), resulting in four non-identical haploid cells (gametes) for genetic diversity.

Meiosis I

Reduces the chromosome number by half and introduces genetic variation.

Meiosis II

Similar to mitosis but without DNA replication, leading to four haploid cells.

Mitosis Significance

Ensures that new cells are genetically identical to the parent cell, maintaining chromosome number.

Meiosis Significance

Crucial for sexual reproduction, ensuring genetic diversity in offspring and maintaining chromosome number.

Walther Flemming

First observed and described mitosis.

Oscar Hertwig

Studied fertilization and meiosis in sea urchins.