2.3 Eukaryotic Cells

2.3.1 Draw and label a diagram of the ultrastructure of a liver cell as

an example of an animal cell.

Ribosomes Golgi Apparatuses Lysosomes

Nuclear MembraneRough Endoplasmic

Reticulum

NucleusMitochondrion

2.3.2 Annotate the diagram from 2.3.1 with the functions of each

named structure.• Golgi Apparatus- for processing proteins (pp.119*)• Lysosomes- hold digestive enzymes (pp.121*)• Nucleus- hold chromosomes (pp.117*)• Mitochondrion- for aerobic respiration (pp. 123*)• Rough Endoplasmic Reticulum – for synthesis of

proteins that will be secreted (pp. 118*)• Ribosomes- for protein synthesis (pp.117*)

*More detailed information from Campbell textbook

2.3.4 Compare Prokaryotic and Eukaryotic Cells

Feature Prokaryotes Eukaryotes

Type of Genetic Material Naked loop of DNA Chromosomes consisting of strands of chromosomes. DNA associated with protein (histones).

Main Location of Genetic Information

Cytoplasm in Nucleoid Nucleus inside double nuclear membrane (nuclear envelop)

Mitochondria Not present. Cell surface membrane and mesosome used instead

Always present

Ribosomes Small sized (70S*) Large sized (80S*)

Organelles bound by single membrane

Few or none present Many present: including endoplasmic reticulum, Golgi Apparatus, Lysosomes

*S=Svedburg Units (system used to measure size of organelles)

Source: http://micro.magnet.fsu.edu/cells/procaryotes/images/procaryote.jpg

Eukaryotic Cell

Source: http://www.biologie.uni-hamburg.de/b-online/library/onlinebio/5_6.jpg

2.3.5 State three differences between plant and animal cells

Feature Animal Plant

Cell Wall Not present. Only have cell surface membrane

Cell wall and cell surface membrane present

Chloroplasts Not present Present for photosynthesis

Carbohydrate Storage

In form of glycogen In form of starch

Vacuole Not usually present. Small/

temporary vacuoles sometimes found

Large fluid-filled vacuoles

Shape Can change shape; rounded

Fixed shape; regular

Animal Cell

Source: http://cmweb.pvschools.net/~bbecke/newell/images/cells/Animal-Cell.jpg

Plant Cell

Source: http://www.molecularexpressions.com/cells/plants/images/plantcell450.jpg

• Detailed pictures of an animal and plant cells can also be seen in the Campbell textbook pp. 114-115.

2.3.6 Outline two roles of extracellular components

1. The plant cell wall maintains cell shape, prevents excessive water uptake, and holds the whole plant up against the force of gravity. The main component of the cell wall is cellulose. Bundle of cellulose is called microfibils. These also give great tensile strength and allow high pressure to develop inside the plant cell.

2. Animal cells secrete glycoproteins (proteins with covalently bonded carbohydrate, usually short chains of sugars) that form the extracellular matrix (ECM). The most abundant glycoprotein in the ECM of most animal cells is collagen, which forms strong fibers outside the cells. The collagen fibers are embedded in a network woven from proteoglycans, which are glycoproteins of another class. The ECM of animal cells function in support, adhesion, movement and regulation.

*More information from Campbell textbook pp.133

Vocabulary List• Ribosomes• Rough Endoplasmic Reticulum• Lysosome• Golgi Apparatus• Mitochondrion• Nucleus• Naked DNA• Cytoplasm• Nuclear Membrane• Organelles• Cell Wall• Chloroplast• Vacuole• Glycoproteins• Cellulose• Extracellular Matrix (ECM)• Collagen

• Proteoglycans• Tensile Strength• Microfibils