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.

RibosomesGolgi ApparatusesLysosomes Nuclear MembraneRough Endoplasmic Reticulum Nucleus Mitochondrion

2.3.2 Annotate the diagram from 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 FeatureProkaryotesEukaryotes Type of Genetic MaterialNaked loop of DNAChromosomes consisting of strands of chromosomes. DNA associated with protein (histones). Main Location of Genetic Information Cytoplasm in NucleoidNucleus inside double nuclear membrane (nuclear envelop) MitochondriaNot present. Cell surface membrane and mesosome used instead Always present RibosomesSmall sized (70S*)Large sized (80S*) Organelles bound by single membrane Few or none presentMany present: including endoplasmic reticulum, Golgi Apparatus, Lysosomes *S=Svedburg Units (system used to measure size of organelles)

Source:

Eukaryotic Cell Source:

2.3.5 State three differences between plant and animal cells FeatureAnimalPlant Cell WallNot present. Only have cell surface membrane Cell wall and cell surface membrane present ChloroplastsNot presentPresent for photosynthesis Carbohydrate Storage In form of glycogenIn form of starch VacuoleNot usually present. Small/ temporary vacuoles sometimes found Large fluid-filled vacuoles ShapeCan change shape; rounded Fixed shape; regular

Animal Cell Source: Cell.jpg

Plant Cell Source:

Detailed pictures of an animal and plant cells can also be seen in the Campbell textbook pp

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