Prokaryotic Cells Overview

Prokaryotic Cells

• Prokaryotic cells are smaller than eukaryotic cells.
• Prokaryotic cells lack a nucleus and membrane-bound organelles.
• Prokaryotic cells have a single, circular chromosome.
• Prokaryotic cells reproduce asexually through binary fission.

Textbook Availability

• Hard copies of the 3rd edition textbook are no longer available from the publisher.
• Used copies of the 3rd edition are available.
• The 3rd edition textbook may be available on reserve at the Scott Library.
• The 4th edition is available but has differences from the 3rd edition.
• The 4th edition can be purchased at the same price as the 3rd edition through an eClass link

Lab 1 Information

• Lab 1 begins the week of September 16th.
• Students are not required to attend an in-lab session for Lab 1.
• The lab can be completed independently and before September 22nd.
• The lab will be conducted using the Simbio virtual lab software.
• Access to the virtual lab software is provided in the Lab 1 section of eClass, with the access key in the "SimUText Registration Instructions for Students (Fall 2024)".
• A lab manual must be purchased before the start of Lab 1.

Quizzes

• An eClass quiz opened today.
• A first Mastering Biology quiz is scheduled for next Monday.
• A practice quiz is available this week for homework and won't affect grades.

Learning Strategies

• Study Cycle
• Using Learning Outcomes
• Metacognition
• 3 Evidence-based Study Strategies

Metacognition

• Metacognition is like having a "big brain" that observes your brain's actions.

Prokaryotes: Bacteria/Archaea

• Refer to last week's posted slides.

Eukaryotic Cells

• Eukaryotic cells have a nucleus and membrane-bound organelles.
• Eukaryotic cells are larger than prokaryotic cells.

The Eukaryotic Cell

• Larger size than prokaryotic cells
• Genome enclosed by a nuclear envelope
• Membrane-bound organelles with specialized functions
• Cytoskeleton with motor proteins

Eukaryotic Cell Structures

• Nucleus (including nuclear lamina, nucleolus)
• Ribosomes
• Endomembrane System (including ER, Golgi, lysosomes, vacuoles)
• Nuclear envelope/membrane
• Mitochondria
• Chloroplasts
• Cytoskeleton
• Plasma membrane
• Cell wall (not peroxisomes)

Animal and Plant Cells

• Learn the basic structure of animal and plant cells.
• Understand the structure and functions of organelles.
• Understand differences between animal and plant cells.

BioFlix: Animal Cell

• The BioFlix study area provides a tour of an animal cell on Mastering Biology.

BioFlix: Plant Cell

• The BioFlix tour of a plant cell is a study resource on Mastering Biology.

Membrane Bound Organelles

• Membrane-bound organelles increase the surface area to volume ratio.
• This allows for more efficient cellular reactions.
• Organelles compartmentalize functions within the cell.

Molecular Movement

• Molecules constantly move throughout the cell and between different structures.

The Nucleus

• The nucleus separates hereditary material from the rest of the cell.
• It's surrounded by a double membrane (nuclear envelope)

The Nuclear Lamina

• Provides structural support to the nucleus.
• Composed of intermediate filaments.

The Nucleolus

• The nucleolus is the site of rRNA synthesis.
• It's a non-membrane-bound structure within the nucleus.
• It's composed of proteins and nucleic acids.
• Ribosomal RNA (rRNA) and ribosomal subunit assembly take place here.

Nuclear Transport

• Nuclear pores control what enters and exits the nucleus.

Nuclear Pore Complexes

• Embedded in the nuclear envelope
• Multiprotein complex that controls traffic between the cytoplasm and nucleus.

Targeting Molecules to the Nucleus

• Larger molecules can be targeted to the nucleus.
• There's a signal sequence that directs the movement.

Signal Sequences

• Signal sequences (e.g. Nuclear Localization Signal (NLS)) regulate the traffic of molecules between the nucleus and cytoplasm.

Endomembrane System

• A collection of interconnected membranes (e.g., nuclear membrane, ER, Golgi)
• Involved in protein synthesis, modification, transport, lipid synthesis, detoxification of toxins, and breakdown of molecules.
• Membranes of the endomembrane system are interconnected directly or can fuse portions of their membranes.

Endomembrane System Evolution

• A hypothesis proposing that all components of the endomembrane system are derived from infoldings of the plasma membrane.

Proteins in the Endomembrane System

• Different parts of the endomembrane system require specific proteins.

Protein Movement

• Vesicles move proteins between the different compartments of the endomembrane system.