Cytogenetics

Karyotype: The number, shapes, and sizes of the metaphase chromosomes in a cell.

Lecture 5 – Ploidy

1

polyploid: several chromosome sets

Tetraploid

SeedlessNew speciesLarger

Triploid

2n + 2n=4n

trisomy 21 – Down’smonosomy

Nondisjunction

aneuploid: chromosome # is not normal

Genetic modification of organisms = GMO

Lecture 5 – Ploidy

2

Ploidy maintained reduced by 1/2

Mitosis vs. Meiosis

Divisions 1 2

Hom. Pairing No Yes

Crossovers No Yes

Assortment - Independent

Promotes No Yesvariation

Lecture 5 – Ploidy

3

1. Cells are the fundamental units of life

2. All organisms are composed of cells

3. All cells come from pre-existing cells

Cell Theory:

Zaccharias & Hans Janssen1590

Leeuwenhoek & Hooke (cells)mid-late 1600s

Observation essential aspect of Biology

Schwann & Schleiden1838

Lecture 6 - Prokaryotic and eukaryotic cells

Scale: 1-100um

Visualization: microscopy- bright field, phase contrast, DIC

- fluorescence, confocal

- Electron (transmission, scanning)

Lecture 6 - Prokaryotic and eukaryotic cells

Basic components of a cell?

“Prokaryotic”

Eukaryoticvs

“before nucleus” “true nucleus”

…?organelles

3 domain system: Archaea, Bacteria, Eukarya

animalplant

Differences?

Fungi

Protista

Bacteria Archaea

Extremophiles (biotech…) - high temp (122oC) - salt - acidic (pH 0) - alkaline

Lecture 6 - Prokaryotic and eukaryotic cells

Cytoplasm

Outer membrane(absent in some bacteria)

Cell wallPeptidoglycan

Capsule

Flagellum

Nucleoid single chromosome no histones

Ribosomes

Plasmamembrane

Basic components of a “prokaryotic” cell?

transcription/translation- coupled!!

Lecture 6 - Prokaryotic and eukaryotic cells

Figure 4.7 Eukaryotic Cells (Part 1)

animal

Eukaryotic

plant

Similarities/Differences?

Lecture 6 - Prokaryotic and eukaryotic cells

Figure 4.7 Eukaryotic Cells (Part 1)

Animal Cell

Mitochondrion

Rough endoplasmic reticulum - membrane & secreted proteins - signal peptide

Free ribosomes

Centrioles - MTOC

Ribosomes(bound to RER) Golgi apparatus

- protein trafficking

Plasmamembrane

Smoothendoplasmicreticulum

Nucleus: DNA, histones, multiple chromosomes linear, nuclear localization signal (NOT SIGNAL SEQUENCE!)

Cytoskeleton: actin/tubulin

Lecture 6 - Prokaryotic and eukaryotic cells

A PLANT CELL

Smoothendoplasmicreticulum

Chloroplast

Plasmodesmata - channels Golgi apparatus

Mitochondrion

Roughendoplasmicreticulum

Nucleus

Freeribosomes

Cell wall

Vacuole

Plasmamembrane

Differences

Lecture 6 - Prokaryotic and eukaryotic cells

Nucleoplasm

Outer membrane

Inner membrane

Nucleolus

Nuclearpore

Nuclearenvelope

Nuclearlamina

Eukaryotic cells – similarities1. Nucleus

Chromatin*Txn!

An

Transcription/Translation- uncoupled!!

Lecture 6 - Prokaryotic and eukaryotic cells

Ribosomes

Inside of cell

Nucleus

Lumen

Lumen

Rough EndoplasmicReticulum

Smooth EndoplasmicReticulum

Eukaryotic cells – similarities2. Endoplasmic reticulum

a. Synthesis of membrane or secreted proteins

b. Modify molecules enter cellc. Synthesis of lipids & steroids

Lecture 6 - Prokaryotic and eukaryotic cells

Nucleus

medialregion

cisregion

Plasma membrane

Proteins for useoutside the cell

Proteins for usewithin the cell

transregion

ER

Golgi apparatusa. Sorting depot for

proteinsb. Plant cell wall

material

Eukaryotic cells – similarities3. Golgi apparatus

Lecture 6 - Prokaryotic and eukaryotic cells

Intermediatefilament MicrotubuleMicrofilaments

Plasmamembrane

Actin monomer

Tubulindimer

-Tubulinmonomer

-Tubulinmonomer

Fibrous subunit

End End End End

Eukaryotic cells – similarities4. cytoskeleton

a. Cell shapeb. Cell movementc. Positions organellesd. Helps anchor celle. Cell divisionf. Molecular transport

Lecture 6 - Prokaryotic and eukaryotic cells

Outside of cell

Golgiapparatus

Plasmamembrane

Phagosome

lysosome

Eukaryotic cells – differences1. Lysosomes vs vacuoles

2. Peroxisomes vs glyoxysomes (only plants)- peroxide breakdown vs lipid storage

3. Mitochondria vs chloroplasts (only plants/protists)

- storage/degradation (autophagy –self digestion, Tay-Sachs)- structure

Lecture 6 - Prokaryotic and eukaryotic cells

Cristae

Matrix

Eukaryotic cells – differences3. Mitochondria vs plastids (e.g. chloroplasts)

StromaThylakoid - chlorophyll

- Energy transformation

Cellular respiration - generate ATP - genome

Photosynthesis - generate ATP - genome

Lecture 6 - Prokaryotic and eukaryotic cells

Eukaryotic cells – differences3. ECM vs cell wall

a. Cell adhesionb. Physical properties of tissuec. Filterd. Cell movemente. Cell signaling

Animal

a. Support and volumeb. Protective barrierc. Part of plant growth

Plant

Lecture 6 - Prokaryotic and eukaryotic cells

Basic components of a cell?Prokaryotic Eukaryoticvs

Differences?

Biotechnology/Synthetic biology – Know basic components of a cell.

Lecture 6 - Prokaryotic and eukaryotic cells