Basic Structure of a Cell 1 Prokaryotic Cell

Basic Structure of a Cell 1

Prokaryotic Cell Label 2

Organelles in Eukaryotic cells 3

1. Cell Membrane Phospholipids Heads - glycerol & phosphate and are hydrophilic Tails - fatty acids and are hydrophobic Make up a bilayer where tails point inward toward each other Can move laterally to allow small molecules (O 2, CO 2, & H 2 O) to enter 4

Cell Membrane Cell membrane proteins Proteins help move large molecules or aid in cell recognition Peripheral proteins are attached on the surface (inner or outer) Integral proteins are embedded completely through the membrane 5

Cell Membrane Glycoproteins • Glycoproteins usually integral proteins that have carbohydrate tails to act as markers for cell recognition Recognize “self” 6

Cell Membrane Composed of double layer of phospholipids and proteins Surrounds outside of ALL cells called the Living layer Controls what enters or leaves the cell If this membrane was not selectively permeable, the cell’s content would be the same as its surroundings. Outside of cell Proteins Carbohydrate chains Cell membrane Inside of cell (cytoplasm) Protein channel Lipid bilayer 7

Cell Membrane Molecules in cell membranes are constantly moving and changing…called fluid mosaic model Least likely to find water 8

2. Cytoplasm • Jelly-like substance enclosed by cell membrane • Provides a medium for chemical reactions to take place • Made up of cytosol (fluid) and protein. • Contains organelles to carry out specific jobs • Found in ALL cells cytoplasm 9

3. Nucleus - The Control Organelle • Controls the activities of the cell • Contains the DNA, • Each cell has fixed number of chromosomes that carry genes • Genes control cell characteristics • Usually the largest organelle 10

Nuclear Envelope Double bilayer membrane surrounding nucleus Contains nuclear pores for materials to enter & leave nucleus Connected to the rough ER Nuclear pores 11

DNA -Inside the Nucleus The genetic material (DNA) is found in the nucleus as… DNA is spread out And appears as CHROMATIN in non-dividing cells DNA is condensed & wrapped around proteins forming as CHROMOSOMES in dividing cells 12

DNA is the hereditary material of the cell • Genes that make up the DNA molecule code for different proteins 13

Nucleolus Inside nucleus Cell may have 1 to 3 nucleoli Disappears when cell divides Makes ribosomes that make proteins 14

3. Mitochondrion (plural = mitochondria) “Powerhouse” of the cell because it generates cellular energy (ATP) More active cells like muscle cells have MORE mitochondria Both plants & animal cells have mitochondria Site of CELLULAR RESPIRATION (burning glucose) 15

MITOCHONDRIA Surrounded by a DOUBLE membrane Has its own DNA Folded inner membrane called Cristae (increases surface area for more chemical reactions) Interior called the Matrix 16

Interesting Fact --- Mitochondria Come from cytoplasm in the EGG cell during fertilization Therefore … You inherit your mitochondria from your mother! 17

What do mitochondria do? “Power plant” of the cell Burns glucose to release energy (ATP) Stores energy as ATP 18

4. Ribosomes Made of PROTEINS and r. RNA “Protein factories” for cell Join amino acids to make proteins Process called protein synthesis 19

Ribosomes Can be attached to Rough ER OR Be free (unattached) in the cytoplasm 20

5. Endoplasmic Reticulum - ER Network of hollow membrane tubules Connects to nuclear envelope & cell membrane Functions in Synthesis of cell products & Transport Two kinds of ER ---ROUGH & SMOOTH 21

Rough Endoplasmic Reticulum (Rough ER) Has ribosomes on its surface Makes membrane proteins and proteins for EXPORT out of cell 22

Rough Endoplasmic Reticulum (Rough ER) Proteins are made by ribosomes on ER surface They are then threaded through the interior of the Rough ER to be modified and transported 23

Smooth Endoplasmic Reticulum Smooth ER lacks ribosomes on its surface Is attached to the ends of rough ER Makes cell products that are used in the cell 24

Functions of the Smooth ER Makes membrane phospholipids Regulates calcium (muscle cells) Destroys toxic substances (Liver) 25

6. Golgi Bodies Stacks of flattened sacs Have a shipping side (trans face) and receiving side (cis face) Receive proteins made by ER Transport vesicles with modified proteins pinch off the ends CIS TRANS Transport vesicle 26

Golgi Bodies Look like a stack of pancakes • Modify, sort, & package molecules from ER for storage OR transport out of cell 27

Golgi Animation • Materials are transported from Rough ER to Golgi to the cell membrane by vacuoles. 28

7. Vacuole In plants, they store Cell Sap Includes storage of sugars, proteins, minerals, lipids, wastes, salts, water, and enzymes 29

8. Cytoskeleton Helps cell maintain cell shape Also help move organelles around Made of proteins Microfilaments are threadlike & made of ACTIN Microtubules are tubelike & made of TUBULIN MICROTUBULES MICROFILAMENTS 30

Two Types of Microtubules Centrioles Cilia & Flagella 31

Cilia & Flagella are longer and fewer (usually 1 -3) on cells Cilia are shorter and more numerous on cells 32

Cell Movement with Cilia & Flagella 33

In the Respiratory System - cilia moves dust particles and mucus out of the lungs 34

9. Centrioles Found only in animal cells Paired structures near nucleus Made of bundle of microtubules Appear during cell division forming mitotic spindle Help to pull chromosome pairs apart to opposite ends of the cell 35

10. Pseudopodia Temporary cytoplasmic movement in amebae or protozoa which function in locomotion and/or in feeding by surrounding their food. One or more may be formed at a time by a given cell. http: //www. youtube. com/watch? feature=player_embedded&v=W OAf 4 z. Dga. Jo Protozoa 36

11. Lysosomes Contain digestive enzymes These enzymes break down food, bacteria, and worn out cell parts (organelles, phospholipids, etc. ) 37

Organelles Specific To Plants 38

12. Cell Wall Cell wall • Nonliving layer: found in plants, fungi, & bacteria • Made of cellulose in plants • Supports and protects cell • Found outside of the cell membrane 39

13. Large Central Vacuole Fluid filled sacks for water storage in plant cells Small or absent in animal cells, unlike plants which have one large Central Vacuole 40

14. Plastid Organelles involved in the synthesis & storage of food. Chromoplasts - carrot root cells - filled with the orange pigment carotene. Chloroplasts use light energy to make carbohydrates from carbon dioxide and water. 41

Chloroplast Found only in producers (organelles containing chlorophyll) never in animal cells. Use energy from sunlight to make food (glucose) Energy from sun is stored in the Chemical Bonds of Sugars 42

Chloroplast Surrounded by DOUBLE membrane and has its own DNA Outer membrane smooth/Inner membrane modified into sacs called Thylakoids Stacks of sacs is called Grana & are interconnected Stroma – gel like material surrounding thylakoids 43

Chloroplast 44