Tour Of The Cell

Microscopy What is the difference between magnification and resolving power? Magnification is how much larger the object can now appear. Resolving power is the ability to distinguish between two points, it is limited by the wavelength of visible light.

The different microscopes: Light microscope - resolving power is limited by the wavelengths of light. Specimen should be stained, but can be alive –Compound microscope –stereomicroscope Electron microscope - resolving power is greater since wavelengths of electrons is smaller than those of light. –SEM - 3D image –TEM - flat image electron microscopes cannot use live specimens

How did scientists first discover the different cell parts?

As Organisms Get Larger, Why do They Become Multicellular?

It’s all about the surface area to volume ratio!

Prokaryotic vs. Eukaryotic Cells Prokaytotic cells: monerans genetic material not in a nucleus no membrane bound organelles Eukaryotic cells: Protists, Plants, Fungi and Animals true nucleus with genetic material has membrane boun organelles

The Prokaryotic Cell:

The Plasma Membrane:

General Eukaryotic Cells:

Two Areas of the Eukaryotic Cell: What is the space between the cell membrane and the nucleus called? The cytoplasm. This includes the organelles and the cytosol. The cytosol is the fluid medium found in the cytoplasm

The nucleus

Nuclear Components: Envelope =

Nuclear Components: Envelope = double layered membrane that has pores for molecular transport. Chromatin =

Nuclear Components: Envelope = double layered membrane that has pores for molecular transport. Chromatin = DNA + protein complex of threadlike fibers that make up the eukaryotic chromosome. Chromosome =

Nuclear Components: Envelope = double layered membrane that has pores for molecular transport. Chromatin = DNA + protein complex of threadlike fibers that make up the eukaryotic chromosome. Chromosome = Chromatin fibers condense into visible chromosomes during cell division.

Ribosomes: Prokaryotic ribosomes differ from eukaryotic ribosomes Function =

Ribosomes: Prokaryotic ribosomes differ from eukaryotic ribosomes Function = Site of Protein synthesis

The Endomembrane system: Related through direct continuity or by transfer on membrane segments through vesicles. Structure of membranes is not identical Includes: Nuclear envelope --> Endoplasmic reticulum --> Golgi apparatus --> lysosomes --> vacuoles -->plasma membrane

Transport vessicle from ER New vessicle forming Transport vessicle from golgi

Function of Golgi: Modifies stores and routes products of ER Alters membrane phsopholipids Targets products for parts of the cell

Vacuoles Larger than vessicles food vacuoles =

Vacuoles Larger than vessicles food vacuoles = formed by phagocytosis contractile vacuole =

Vacuoles Larger than vessicles food vacuoles = formed by phagocytosis contractile vacuole = found in fresh water protozoans, keep water balancecontractile vacuole central vacuole =

Vacuoles Larger than vessicles food vacuoles = formed by phagocytosis contractile vacuole = found in fresh water protozoans, keep water balance central vacuole = found in most plant cells stores organic compounds, has enzymes to break macromolecules, has poisonous and unpalatable compounds,etc...central vacuole

Mitochondria and Chloroplasts Not part of endomembrane system their membrane proteinsare made by free ribosomes and their own ribosomes Both have small amount of DNA Grow and reproduce on their own within the cell Involved in Energy transformation

Plastids Amyplasts - store starch, in roots and tubers chromoplasts - non-chlorophyll pigments responsible for non-green colors. Chloroplasts - chlorophyll containing plastids

Peroxisome Contains enzymes that transfer hydrogen from substrates to oxygen, producing hydrogen peroxide. Some use oxygen to fuel the breakdown of fatty acids to smaller molecules that can be used in the mitochondrion. In liver they detoxify alcohol and other poisons, by transferring hydrogen from poison to oxygen Hydrogen peroxide is toxic, what enzyme can be used to break this down?

Cytoskeleton Provides structural support Functions in motility and motion

Microtubules Cellular support provides tracks for movement within the cell: e.g. transport vessicles Composes cilia and flagella, locomotive appendages of certain cells. separation of chromosomes during cell division (spindle fiber) composes centrioles in animal cells

Microfilaments Smaller than microtublues participates in muscle contraction support localized cell contractions

The Cell Surface Cell Walls in plant cells membrane linked channel - plasmodesmata that connects cytoplasm between cells

Animal Cell Surfaces Glycocalyx - strengthens cell surface, helps glue animal cells together tight junctions - holds cells together to block transport desmosomes - rivets cells together into strong sheets but permits transport gap junctions - analogous to plasmodesmata in plant cells

Let’s Review: Name the cell structure and its function. Be able to tell if this structure is found in prokaryote, eukaryote, plant and/or animal cells

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