Eukaryotic Cell Substructure Plant and Animal Cells

ANIMAL CELL

Mitochondria Structure - composed of modified double unit membrane (protein, lipid) -inner membrane infolded to form cristae -Function - site of cellular respiration ie. the release of chemical energy from food Glucose + Oxygen > Carbon Dioxide + Water + Energy (ATP) DNA Inter-membrane space

Cytoskeletal structures Cells contain elaborate arrays of protein fibers that serve such functions as: Establishing cell shape Providing mechanical strength Locomotion (cilia, flagella) Chromosome separation in mitosis and meiosis Intracellular transport of organelles

Major components of cytoskeletal system Intermediate Filaments Microtubules Actin filaments

Centrioles a pair of cylinder-like structures. function in cell division. made up of nine bundles of microtubules found only in animal cells.

Rough and Smooth Endoplasmic Reticulum Endo means within Plamic refers to the cytoplasm Reticulum means a network. Thus the endoplasmic reticulum is a series of interconnected, intracytoplasmic, membrane bounded sacs.

Rough endoplasmic reticulum (RER) appear rough due to presence of ribosomes involved in protein synthes is. Smooth endoplasmic reticulum (SER) has no ribosomes The SER is involved in cholesterol metabolism, membrane synthesis, (Lipids) Detoxification, Ca++ storage along with other cellular processes.

Vesicles Membrane bound intracellular sacs transport vesicles endocytotic vesicles exocytotic vesicles lysosomal vesicle secretory vesicle adipose vesicles

Golgi Apparatus/Body Proteins are transported from the RER to the golgi apparatus and from the golgi apparatus to the plasma membrane in transport vesicles.

Lysosmes A primary lysosome contains many enzymes synthesized in the RER and sorted in the golgi.

Peroxisomes/Micorbodies Organelles that contain enzymes to degrade fatty acids and amino acids. – A biproduct of this degradation is H 2 O 2 hydrogen peroxide – highly toxic to proteins Also contain the enzyme catalase which destroys H 2 O 2 The enzymes are synthesized on the RER and are sorted/refined into the peroxisomes in the golgi apparatus

PLANT CELL

How Plant and Animal Cells Differ PLANT CELLS Cell walls present Plastids occur in cytoplasm Lysosomes not usually evident Centrioles present only in cells of lower plant forms Large vacuoles filled with cell sap ANIMAL CELLS No cell walls No plastids are found Lysosomes occur in cytoplasm Centrioles always present Vacuoles, if present, are small and contractile or temporary vesicles

Cell Wall Cell walls are made of specialized sugars called cellulose. Cellulose is called a structural carbohydrate (complex sugar) because it is used in protection and support.

Cell Wall Function help a plant keep its shape protect the cells allow plants to grow to great heights For smaller plants, cell walls are slightly elastic

Plastids Large cytoplasmic organelles found in the cells of most plants There are three plastid categories- – Leucoplasts (white or colorless plastids that store starch granules), – Chromoplasts (colored plastids that store pigment molecules like cartenoids which store yellow and orange pigment) – Chloroplasts which are essential in the photosynthetic process

Leukoplasts non-pigmentous, 2x5 µm, variable shaped plastids for storage 3 types: AMYLOPLASTS (starch), ALEUROPLAST (protein), ELAIOPLASTS (oils)

Chromoplasts Chromoplast are derived from chloroplast. Synthesize carotenoid pigments such as carotene or lycopene. Found in flowers, fruit, and leaves in stress or senescence. In flowers, carotenoid pigment enables the forming of different color, which can attract insects and other pollinators.

Chloroplasts Site of photosynthesis. 500,000 chloroplasts per square millimeter of leave surface Contain chlorophyll, the green pigment that absorbs energy from sunlight Sunlight captured by chlorophyll enables carbon dioxide from the air to unite with water and minerals from the soil and create food. Chlorophyll gives plants their characteristic green color. DNA

Questions 1.What are the similarities and differences between plant and animal cells? 2.Explain what is meant by the statement "The cell is the functional unit of life.” 3. _______ are known as the 'sites of intracellular digestion'. 4. _______ consist of enzymes, which help in digestion. 5. _______ are known as the 'power-houses of the cell'. 6. Ribosomes are found attached on the _______. 7.Why don't animal cells need cell walls? 8.The green color of leaves is due to the presence of the _______ pigment. 9. The network of convoluted tubules is called the _______. 10. Secretory granules are formed by the _______ of the animal cell. 11. _______ are known as the 'sites of protein synthesis in the cell'. 12.Cell organelle that imparts colour to flowers ________

Task Use your textbook to write descriptions of the following: Cytoplasm Cilia Flagella