Today s materials: Cell Structure and Function. 1. Prokaryote and Eukaryote 2. DNA as a blue print of life Prokaryote and Eukaryote. What is a cell?

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Cell Structure and Function All living things

1 Today s materials: 1. Prokaryote and Eukaryote 2. DNA as a blue print of life Prokaryote and Eukaryote Achadiah Rachmawati What is a cell? Cell Structure and Function All living things are made of cells the basic units of structure and function Biologi Achadiah Rachmawati 1

Cell Theory Cell Theory is only about 150 years

things. 3) All cells come from preexisting cells.

Bacteria Nerve Cell Red Blood Cell Types of Cells

2 Cell Theory Cell Theory is only about 150 years old. 1) All living things are made up of one or more cells. 2) Cells are the basic living units of all living things. 3) All cells come from preexisting cells. (Every living thing begins as one cell than the cells divide and the thing grows!) Examples of Cells Amoeba proteus Plant Stem Bacteria Nerve Cell Red Blood Cell Types of Cells Cell Types Cell Parts Eukaryotic Cells Prokaryotic Cells Organelles Plant Cells Animal Cells Biologi Achadiah Rachmawati 2

Nuclear region is the area that controls all the cell s function and stores the DNA.

3 Surrounding the Cell Cells Cells have three basic components a plasma membrane, a central nuclear region, and cytoplasm. Plasma membrane is the surface of the cell that protects the cell and allows for food and waste exchanges. Nuclear region is the area that controls all the cell s function and stores the DNA. (Some cells are missing this area, but don t reproduce.) Cytoplasm is the gel-like substance filling the cell between the plasma membrane and the nuclear region. Biologi Achadiah Rachmawati 3

Middle lamella is first produced when new cell walls are formed.

4 Cell Wall Main structural component of cell walls is cellulose. Also contain matrix of hemicellulose, pectin, and glycoproteins. Middle lamella is first produced when new cell walls are formed. Secondary walls are derived from primary walls by thickening and inclusion of lignin. Communication Between Cells Fluids and dissolved substances can pass through primary walls of adjacent cells via plasmodesmata. Cytoplasmic strands extending between cells. Symplast = supercell? Biologi Achadiah Rachmawati 4

5 Plasma Membrane Cellular Components Composed of phospholipids arranged in two layers, with proteins interspersed throughout. Some proteins extend across the entire width, while others and embedded to the outer surface. Nucleus Inside the Cell Nucleus is bound by two membranes, which together constitute the nuclear envelope. Structurally complex pores occupy up to one-third of the total surface area. Contains fluid nucleoplasm Nucleolus composed primarily of RNA. Chromatin Strands - Coil and become chromosomes. Biologi Achadiah Rachmawati 5

Chromosomes In nucleus Made of DNA Contain instructions for traits &

6 Chromosomes In nucleus Made of DNA Contain instructions for traits & characteristics Endoplasmic Reticulum Endoplasmic Reticulum facilitates cellular communication and materials channeling. Enclosed space consisting of a network of flattened sacs and tubes forming channels throughout the cytoplasm. Ribosomes may be distributed on outer surface (Rough ER). Associated with protein synthesis. Smooth ER is devoid of ribosomes and is associated with lipid secretion. Biologi Achadiah Rachmawati 6

Dictysomes (Golgi Bodies in animals) are often bound by branching tubules

Dictysomes Plastids Chloroplasts are the most conspicuous plastids.

Contain grana made up of thylakoids. Thylakoid membranes contain chlorophyll.

7 Dictysomes (Golgi Bodies in animals) are often bound by branching tubules that originate from the ER. Dictysomes Plastids Chloroplasts are the most conspicuous plastids. Each bound by double membrane. Contain stroma - Enzyme-filled matrix. Contain grana made up of thylakoids. Thylakoid membranes contain chlorophyll. Chromoplasts and Leucoplasts are additional plastids found in many plants. Mitochondria Site of cellular respiration Biologi Achadiah Rachmawati 7

Microbodies Microbodies are small, spherical bodies with a single membrane, distributed throughout the cytoplasm which contain specialized enzymes. Perixosomes - Serve in photorespiration.

8 Microbodies Microbodies are small, spherical bodies with a single membrane, distributed throughout the cytoplasm which contain specialized enzymes. Perixosomes - Serve in photorespiration. Glyoxisomes - Aid in converting fat to carbohydrates. Vacuoles In mature cells, 90% of volume may be taken up by central vacuoles bounded by vacuolar membrane (tonoplast). Filled with cell sap which helps maintain pressure within the cell. Also frequently contains water-soluble pigments. Cytoskeleton Cytoskeleton is an intricate network of microtubules and microfilaments. Microtubules control the addition of cellulose to the cell wall. Microfilaments play a major role in the contraction and movement of cells in multicellular animals. Appear to play a role in cytoplasmic streaming. Biologi Achadiah Rachmawati 8

Special Parts: PLANT CELLS Chloroplasts Cell Wall Chloroplasts One of the

ability to conduct photosynthesis, in effect, to make their own food by

Cell Wall One of the most important distinguishing features of plant cells

The relative rigidity of the cell wall renders plants sedentary, Special

these microscopic organelles is to serve as digestion compartments for

9 Special Parts: PLANT CELLS Chloroplasts Cell Wall Chloroplasts One of the most widely recognized and important characteristics of plants is their ability to conduct photosynthesis, in effect, to make their own food by converting light energy into chemical energy. Cell Wall One of the most important distinguishing features of plant cells is the presence of a cell wall. The relative rigidity of the cell wall renders plants sedentary, Special Parts: ANIMAL CELLS Lysosome Centrosomes Lysosome The main function of these microscopic organelles is to serve as digestion compartments for cellular materials that have exceeded their lifetime or are otherwise no longer useful. Centrosomes Found only in animal cells, these paired organelles are typically located together near the nucleus in the centrosome, a granular mass that serves as an organizing center for microtubules. Biologi Achadiah Rachmawati 9

Prokaryotes Unicellular Reproduce asexually Composition Protected interior (cytoplasm) that contains genetic material (one circle of DNA) as well as complexes of protein enzymes to carry out

2-10 micrometer (µm) Composition Phospholipid membrane, many contain cell wall composed of peptidoglycan (positive for chemical Gram stain), those with little or no peptidoglycan called Gram negative

2-10 µm often multicellular, some have cell walls (no peptidoglycan) usually single-celled, some have peptidoglycan cell walls Metabolism usually need oxygen to exist may not need oxygen to exist

10 Prokaryotes Unicellular Reproduce asexually Composition Protected interior (cytoplasm) that contains genetic material (one circle of DNA) as well as complexes of protein enzymes to carry out necessary functions of gathering energy, manufacturing proteins (ribosomes), etc. Prokaryotes Size micrometer (µm) Composition Phospholipid membrane, many contain cell wall composed of peptidoglycan (positive for chemical Gram stain), those with little or no peptidoglycan called Gram negative (like Coxiella) Eukaryotes Prokaryotes DNA Organization linear strands within membranebound single circle in nucleoid nucleus region Size µm µm often multicellular, some have cell walls (no peptidoglycan) usually single-celled, some have peptidoglycan cell walls Metabolism usually need oxygen to exist may not need oxygen to exist Organelles membrane bound organelles like mitochondria no organelles, different ribosomes Examples plants, animals, protists, fungi bacteria, archaea 39 Eukaryotes Uni- or multicellular. Reproduce asexually & sexually. Composition: Genetic material (long linear strands of DNA chromosomes) especially isolated and enclosed in membrane (nucleus) Some have cell walls (plants have cellulose, fungi ß- glucan) 40 Biologi Achadiah Rachmawati 10

Eukaryotes Eukaryotic Organelles Animal Cell Plant Cell Size

transforming cellular energy and manufacturing macromolecules.

Mitochondrion Eukaryote vs. Prokaryote Golgi Chloroplast 43 eg.

bacteria animals plants unicellular organisms: yeast,

11 Eukaryotes Eukaryotic Organelles Animal Cell Plant Cell Size (µm) Composition: Phospholipid membrane outside, as well as inside. Interior membranes separate functions such as gathering and transforming cellular energy and manufacturing macromolecules Eukaryotic Organelles Endoplasmic reticulum Nucleus Mitochondrion Eukaryote vs. Prokaryote Golgi Chloroplast 43 eg. fungi eg. bacteria animals plants unicellular organisms: yeast, Dictyostelium etc. Biggest differences: Prokaryotes lack a nuclear membrane! Prokaryotes don't have intracellular organelles! Prokaryotes about 10X size of Eukaryotes. Biologi Achadiah Rachmawati 11

12 We continue to the next material. DNA as a blue print of life Biologi Achadiah Rachmawati 12

Basic Structure of a Cell

Basic Structure of a Cell Prokaryotic Cells No nucleus Archaea & Eubacteria One circular chromosome Extremely small Eukaryotic Cells Has a nucleus!!! Membrane-bound organelles Plants, Animals, Fungi, &