Prokaryotic and Eukaryotic Cells -

Overview

  • Topic: Distinguishing prokaryotic and eukaryotic cells by distinguishing features.

  • Source content covers major structures, comparison, and practice identifying organelles in prokaryotes vs eukaryotes.

  • Includes a taxonomy of organisms (Archaea, Bacteria, Eukarya) and a basic activity analyzing presence/absence of organelles in cell types.

What is a cell?

  • All organisms are made up of one or more cells.

  • The basic unit of structure and function of all living organisms.

  • New cells are produced from pre-existing cells.

Key concepts and objectives

  • Distinguish prokaryotic and eukaryotic cells according to distinguishing features.

  • Identify major structures present in prokaryotic and eukaryotic cells.

  • Compare and contrast prokaryotic and eukaryotic cells.

  • Identify prokaryotic and eukaryotic organisms.

Prokaryotic cell components (as listed in the transcript)

  • Plasma membrane

  • Cytoplasm

  • Nucleoid (DNA)

  • Ribosomes

  • Cell wall

  • Capsule

  • Pili (Pilus)

  • Flagellum

  • Mesosome

  • Plasmid

  • DNA (genetic material within the nucleoid region)

  • Peroxisome (noted in the prokaryotic context in the transcript; typical prokaryotes do not have a true peroxisome, but the slide includes it among organelles listed for consideration)

Eukaryotic cell components (as listed in the transcript; with plant-specific examples)

  • Plasma membrane

  • Cytoplasm

  • Nucleus (contains nucleolus and nuclear membrane)

  • Ribosomes

  • Endoplasmic reticulum (rough and smooth)

  • Golgi apparatus

  • Mitochondrion

  • Chloroplast (primarily in plants and some algae)

  • Vacuole (large central vacuole in plants; others have smaller vacuoles)

  • Plasmodesmata (plant cell connections)

  • Nucleolus

  • Nuclear envelope

  • Non-membrane bound components: centrosome, cytoskeleton, cell wall (in plants, fungi), plasmodesmata, etc.

Anatomy highlights: Plant cell vs general eukaryotic features

  • Plant cell-specific organelles/features: Chloroplasts, Large central vacuole, Plasmodesmata, Cell wall.

  • General eukaryotic features: Nucleus with nuclear envelope and nucleolus; membrane-bound organelles (ER, Golgi, mitochondria, chloroplasts in plants); cytoskeleton; ribosomes; plasma membrane.

  • Non-membrane bound components: Centrosome (in many animal cells), cytoskeleton, etc.

Activity: organelle presence in Prokaryotic vs Eukaryotic cells

  • Prokaryotic cell versus Eukaryotic cell: presence (√) or absence (X) of various components:

    • Plasma membrane: present in both (√, √).

    • Cytoplasm: present in both (√, √).

    • Nucleus (and subparts):

    • Nucleus: Prokaryotic X; Eukaryotic √.

    • Nuclear membrane: Prokaryotic X; Eukaryotic √.

    • Nucleolus: Prokaryotic X; Eukaryotic √.

    • Genetic material (DNA): present in both (√, √) (note: prokaryotes have DNA in the nucleoid region, not within a nucleus).

    • Cell wall: Present in both (√, √).

    • Ribosomes: Present in both (√, √).

    • Vacuole: Present in both (√, √).

    • Membrane-bound organelles (ER, Golgi, Chloroplast, Mitochondrion): Prokaryotic X; Eukaryotic √ for all listed.

    • Other organelles (write): Capsule, plasmid: Prokaryotic √; Eukaryotic X.

    • Mesosome, flagellum, pilus: Generally associated with prokaryotes (listed as X or not present under typical eukaryotes in this activity).

Summary of domain organization (as shown in the transcript)

  • Archaea, Bacteria, Eukarya are the primary domains/groups:

    • Archaea: Methanogens, Halophiles, Thermophiles (organisms typical of Archaea).

    • Bacteria (Eubacteria): Cyanobacteria among others.

    • Eukarya: Animals, Protists, Fungi, Plants.

  • PROKARYOTA encompasses Archaea and Bacteria; Eukarya includes the aforementioned eukaryotic kingdoms.

Questions to review (based on activity)

  • a) What major structures are found only in prokaryotic cells?

    • Nucleoid (DNA not enclosed in a nucleus), Capsule, Plasmids, Mesosome/ Pili/ Flagella (organelles not typically membrane-bound).

  • b) What major structures are present only in eukaryotic cells?

    • Nucleus with nuclear envelope, Nucleolus, and membrane-bound organelles (ER, Golgi, mitochondria, chloroplasts, lysosomes, etc.).

  • c) What structures are common to prokaryotic and eukaryotic cells?

    • Plasma membrane, Cytoplasm, Ribosomes, DNA (in some form).

  • d) What are the major differences between prokaryotic and eukaryotic cells?

    • Location of genetic material (nucleoid vs nucleus), presence vs absence of membrane-bound organelles, level of cellular compartmentalization and organizational complexity.

Practice activity (classification)

  • Exercise: Given a set of organisms, determine whether they have prokaryotic or eukaryotic cells by writing P for prokaryotic or E for eukaryotic.

  • Note: The transcript lists this as an exercise (no specific organisms provided in the text excerpt).

General concepts and classifications

  • Generalization 1: How are cells classified as prokaryotic or eukaryotic? Based on the presence or absence of a nucleus, the presence or absence of membrane-bound organelles, and the overall cellular organization.

  • Generalization 2: Differentiation criteria:

    • DNA location: nucleoid (no membrane) vs nucleus (membrane-bound).

    • Membrane-bound organelles: present in eukaryotes; absent in prokaryotes.

    • Complexity of organization: more compartmentalization in eukaryotes due to organelles.

Quick reference: key terminology and groupings

  • Prokaryotes include two major domains: Archaea and Bacteria (Eubacteria), collectively referred to in the transcript as PROKARYOTA.

  • Archaea subgroups highlighted: Methanogens, Halophiles, Thermophiles.

  • Bacteria examples noted: Cyanobacteria (photosynthetic), among others.

  • Eukarya includes Animals, Protists, Fungi, Plants.

  • Plant cells feature plasmodesmata, chloroplasts, vacuoles, a cell wall; animal cells do not have plasmodesmata or chloroplasts and have centrosomes.

Formulas or numerical references
  • None explicitly provided in the transcript. All content is descriptive and comparative rather than mathematical.

If you’d like, I can tailor these notes to focus more on the areas you expect to see on the exam (e.g., more emphasis on the organelle presence/absence table, or on the domain organization).