Cellular Biology

1. Cellular Biology The Modern Cell Theory: Has 3 main aspects- 1) The cell is the basic unit of structure and function for life! 2) All organisms are made up of one or more cells! 3) Only cells can produce other cells!!!

2. 1665 Robert Hooke viewed cork samples using a microscope. He viewed tiny repeating structures which looked like Monk’s chambers (which were called cells). Hooke referred to these as cells. 1839 Theodor Schwann argued that cells of living matter could “spontaneously appear” out of disorganized raw material: This was referred to as Spontaneous Generation!!! Cell- Is considered to be the basic unit of living matter in all organisms. Tissue- Large collection of similar cells that perform a specific function in an organism. Organs- Organs are composed of different types of tissue. Organs are a distinct part of the organism that performs one or more particular functions for the organism Organism- Is an individual life form capable of life, capable of growing and reproducing. Composed of one or more cells!!!

3. What must a cell be able to do? • Interact with its environment A) Membrane or cell wall B) Stuff in-stuff out C) Sensory-perception-reaction 2) Produce energy A) Convert raw material to energy B) Obtain raw materials 3) Locomotion- ability of the cell or organism to move A) Pseudopod- “false foot”, projection of the cell or organism that helps it move or feed B) Flagella C) Cilia 4) Waste removal A) Lysosomes B) Exocytosis 5) Protein synthesis 6) Reproduction 7) Provide protection- Ex-Golgi apparatus!!!

4. Components Of A Animal Cell (Eukaryotic) Eukaryotic (Eukaryotes if they are one celled organisms)- Cells that have a nucleus Have a nuclear membrane (also called a nuclear envelope) Are usually larger Are usually more complex (have more organelles) Examples- Animal cells, plants cells, protists Prokaryotic (prokaryotes)- Cells that have no true nucleus Have no nuclear membrane (nuclear envelope) Usually smaller than eukaryotic cells Usually less complicated than eukaryotic cells Examples- Bacteria, archaea!!!

5. Organelles These are specialized components of the cell. Have special form and purpose regarding: Operation Maintenance Repair Reproduction Cell membrane- Semi-permeable Controls movement of molecules in and out of cell Provides interaction with environment around the cell Provides shape and protection for the cell!!!

6. Nucleus- Control center for all cell activity Contains chromosomes (genetic material) Contains compact genetic material (nucleolus) Nuclear membrane (nuclear envelope) surrounds, encloses and protects the nucleus. This is not found in prokaryotic cells, instead they have a nucleoid region!!!

7. Mitochondria- Called the powerhouse of the cell Most of cellular respiration occurs in the mitochondria, thus most ATP is made here Has a double membrane, outer continuous membrane, and a folded inner membrane. Chemical reactions for cellular respiration occur on the inner folded membrane. There may be up to 2000 mitochondria in certain types of cells like skeletal muscle, where tremendous amounts of energy is needed. Ribosomes found in the mitochondria!!!

8. Ribosomes- Sites of protein synthesis (where proteins are made in the cell) Found mostly on rough endoplasmic reticulum Also found in Mitochondria, chloroplasts (in plant cells, protists) May also be found in the cytoplasm M-RNA travel here from the nucleus (in animal cells) to make proteins!!!

9. Endoplasmic reticulum- Transportation ducts throughout the cell Transports proteins made at the ribosomes Ribosomes found on rough endoplasmic reticulum Smooth endoplasmic reticulum produces mucus and found in tissue like the liver!!!

10. Golgi Apparatus (Body) Looks like stacked sacs, that get smaller from one end to the other! Carbohydrates and proteins are refined and repackaged here! Membrane material is recycled here! Vesicles are produced and sent off to other areas of the cell or out of the cell! Also makes mucus for cell protection!!!

11. Lysosomes Called the garbage man of the cell! May contain up to 40 different digestive enzymes! Digests food particles, microorganisms and old worn out cellular organelles in the cell! It is a mystery, why the lysosomes do not digest the cell itself!!!

12. Microtubules Provide structure in the cytoplasm for the cell, gives the cell shape! The cell can build things out of microtubules and break down these structures very quickly! Microtubules are a key component in structures like mitotic spindles (spindle fibers), centrioles, cilia, flagella and the formation and movement of pseudopodia! Microtubules also involved in the movement of other cellular organelles inside the cell!!!

13. Cytoplasm Jellylike material inside of cells where most chemical reactions take place! Most of the other organelles are found inside of the cytoplasm!!!

14. Plant cells Found in plant cells, and not in animal cells: 1) Chloroplasts- A) Capture energy from the sun and use it to make their own food (glucose), photosynthesis! B) Some of this food is used to make energy. C) The rest of this sugar is stored (starch). D) Energy is captured with chlorophyll (pigment within the chloroplast). 2) Central vacuole- A) Water and other materials can be stored here (salts, proteins and carbohydrates). B) Water in the vacuole made provide support for smaller plants 3) Cell wall- A) Is made of different material for plants, bacteria and protists B) Found outside of the cell membrane C) Supports and protects the cell, especially from dehydration D) made of cellulose Found in animal cells and not plant cells: 1) Lysosomes- A) Structures similar to the central vacuole in plants B) Remember, animal cells take in food, rather than make it themselves, must be digested!

15. Protists- Very strange and diverse, mostly unicellular organisms. May be animal-like, plant-like or both! • Euglena- A) Both animal and plant-like organisms, unicellular! B) It is plant-like because it contains chloroplasts, and has the ability to make its own food: photosynthesis! C) Chlorophyll is a pigment (green) in the chloroplasts that captures light energy for photosynthesis. D) It is animal-like because it can move about in the water using flagella (whiplike tail made of microtubules), and will feed on other organisms. E) Has eyespots- which are pigmented organelles F) Eyespot is not used to “see”, but can detect light. G) When the eyespot detects light, the euglena will move toward the light using its flagella, so that the organism may carry on photosynthesis!!!

16. 2) Amoeba- • Unicellular protist • Animal-like • Irregularly shaped • Uses pseudopodia: i) For movement ii) For feeding, forms a food vacuole to obtain nutrition, phagocytosis (endocytosis), food vacuole will fuse with a lysosome to form a phagolysosome, where digestion takes place! Has no anus so waste may exit anywhere on the organism’s membrane! E) Water may enter the organism anywhere, bringing oxygen into the organism as well. F) Excess water is expelled through the contractile vacuole! G) Found in water environments and moist leaves or soil!!!

17. 3) Paramecium- • Animal-like unicellular organism • Found in ponds and slow moving streams • Covered by cilia- used for locomotion • Feeds upon bacteria, algae and other tiny organisms. • Food enters the oral groove, placed in vacuoles, digested, waste is expelled out of the anal pore! • Contractile vacuole pumps out excess water from the organism. • Paramecium contains 2 nuclei- i) Macronucleus is related to normal cell activity ii) Micronucleus is needed when animal engages in sexual reproduction. (asexual, but individual animals may link up and exchange genetic information)!!!

18. 4) Volvox- • This is a type of algae • Unicellular, but live in colonies • Similar to Euglena: i) Have eyespots ii) Have flagella for movement D) Are plant-like only E) Will only use photosynthesis to make its food F) Will team up with other volvox, 500 to 60,000 to form a hollow ball. Cells near the surface whip 2 small flagella to propel the “colony” toward one direction. The colony will tumble as it moves! G) Daughter colonies will live within the parent colony until they have matured enough to live on their own! H) Reproduction- Some species will reproduce sexually, sharing genetic infofrmation, others asexually!!!

19. Types of cells in your body! Red blood cells (RBC)- Also called erythrocytes Have no nucleus Do not reproduce (divide) Live only about 120 days, go to the spleen to die Very specialized to carry oxygen from your lungs to the other cells of your body, and carbon dioxide from cells back to your lungs! Has red pigment, hemoglobin, which gives blood its red color Hemoglobin has 4 binding sites for oxygen Hemoglobin is a protein, very complex (quaternary structure)!!!

20. White blood cells (WBC)- Also called leukocytes Have a nucleus Do not have any hemoglobin Are larger, but less numerous than RBC Major functions: Reduce inflammation Fight infection Respond to allergies and parasites There are 5 types of WBC: Neutrophils Eosinophils Basophils Lymphocytes Monocytes!!!

21. Muscle cells- There are 3 types of muscle cells: 1) Skeletal- Voluntary muscle You think about moving this type This is muscle attached to bone Has alternating stripes (striated) 2) Smooth- Involuntary muscle You do not think about moving this type Surrounds organs: stomach, esophagus, arteries 3) Cardiac- Heart muscle (works all the time) Similar to skeletal (striated), but has intercalated discs Intercalated discs are communicating channels between adjacent heart muscle cells!!!

22. Epithelial cells- Provide an outer covering for our bodies and anywhere the body contacts the external environment: skin, stomach, mouth, urinary tract, etc! Provides sensations: Soft touch/tickling Pressure Hot/cold Interacts with the environment: Fluid regulation Reacts to adverse stimuli!!!

23. There are 3 basic types of epithelial cells: 1) Squamous cells- Flat Usually surface cells like on the top of your skin, inside your cheeks, alveoli of your lungs. 2) Cuboidal cells- Square shaped surrounds holes in the body, creates tubes like in the kidneys. 3) Columnar cells- Rectangular shaped Are deeper and stronger type of cells Found in the stomach, respiratory passages!!!

24. Skin cells- Epidermis- Outer layers of skin cells There are 4 layers, except in the palms of your hands or the soles of your feet (in these areas there are 5 layers of cells, with the extra layer called the stratum lucidum) Dermis- Inner layer of skin cells In this region you will also see: Hair follicles Muscle fibers Blood vessels Nerve endings Sweat glands!!!

25. Nerve cells- Excitatory, will react to stimuli Sensory capabilities are due to nervous system May be up to 3 feet long Have the following structures: Dendrites Soma Axon hillock Axon Myelin sheath Nodes Of Ranvier Terminal end buttons Vesicles Will release neurotransmitters within vesicles across a synapse, which will affect an effector (another nerve, a muscle, a gland (release hormones)!!!

26. Cell cycle and cell division! The cell cycle is a continuous intermittent process where: 1) Cells grow 2) Cells make copies of their chromosomes 3) Parent cells divide to form daughter cells The cell cycle has 3 stages: 1) Interphase- A) This was once thought to be a resting stage for cells in the cell cycle B) Most of the cell cycle is interphase C) Interphase has 3 stages: i) G1 (The first growth stage) a) Cell increases in size b) Number of organelles almost doubles c) Amount of cytoplasm almost doubles ii) S (Synthesis stage) a) Where the number of chromosomes will double (duplicate) iii) G2 (The second growth stage) a) All structures needed for mitosis will form during this stage Ex- Centrioles, spindle fibers!!!

27. 2) Mitosis- A) This is the 2nd phase of the cell cycle B) This is the process where the cell nucleus divides to form 2 new nuclei, each having a complete set of chromosomes. C) A cell that has a full set of chromosomes is said to have a diploid number of chromosomes! D) Sex cells (called gametes), ex- egg or sperm, will have ½ the number of chromosomes, and are said to have a haploid number of chromosomes. E) There are 5 stages of Mitosis: i) Prophase- a) Membrane around the nucleus breaks down c) Centrioles move to opposite sides of the cell ii) Prometaphase- a) Nucleoli disappears b) Nuclear membrane disappears c) Chromosomes become more condensed

28. iii) Metaphase- a) Chromatid move to cell’s center by spindle fibers b) Chromatid line up along equator of the cell iv) Anaphase- a) Spindle fibers pull apart chromatids at their centromeres b) Each chromatid is a duplicate of the parent nuclei c) Spindle fibers pull one half of each chromatid toward opposite end of the cell v) Telophase- a) Spindle fibers disappear as chromosomes move to opposite ends of the cell b) New nucleus membranes form, thus 2 new nuclei form around the chromosomes at each end of the cell There used to be only 4 stages: Prophase, metaphase, anaphase and telophase!!!

29. 3) Cytokinesis- A) This is the final step of the cell cycle B) This is the division of the cell cytoplasm C) Formation of new cell membrane between the 2 new nuclei D) When complete, there will be 2 new daughter cells, each with identical sets of chromosomes E) Usually begins at the end of anaphase!!!

30. Reproductive cell: Involves meiosis- Which is a process that animal cells use for sexual reproduction. Sexual reproduction- Reproduction that occurs when 2 different cells merge together to form a new organism. Gametes- Are sex cells, they have ½ the number of chromosomes compared to a regular body cell. In males this is the sperm, and in females this is the egg! Gametes are called haploid cells, and regular body cells are diploid (full number of chromosomes)!!!

31. How materials move across membranes! • Diffusion- Some things like gases (oxygen and carbon dioxide) will move across a membrane by diffusion. Diffusion is a type of passive transport! Passive transport is where no energy has to be used by the cell! During diffusion, molecules will spread out moving from an area of high concentration to an area of low concentration! See the board! Ex- Oxygen enters a cell via diffusion Ex- Carbon dioxide leaves a cell via diffusion See the board!!!

32. Diffusion occurs because particles (molecules) are randomly moving in all directions, trying to distribute themselves evenly. Keep in mind, as temperature goes up, the speed of the movement of the particles increases, therefore the number of collisions increases, and the particles move farther apart! Also the greater the difference in the 2 areas, the faster the diffusion will occur. Remember: Diffusion is a type of passive transport, thus no energy is needed or used by the cell to accomplish the movement of molecules!!!

33. 2) Osmosis- Is another type of passive transport! This is involving the movement of water across a membrane! This will consider how much solute exists inside Vs. outside of the cell: Hypertonic Hypotonic Isotonic 3) Facillitated diffusion- Passive transport across a membrane which is aided by proteins Different types of proteins help certain molecules move across membranes!!!

34. 4) Active transport- This is a process where a cell will use energy to move material across a membrane. Usually occurs from an area of low concentration to an area of high concentration (but not always)! Types of active transport: A) Endocytosis- Refers to moving material into the cell i) Phagocytosis- Where a cell forms a vacuole, which moves food or material into a cell. This is also called “cell eating”! ii) Pinocytosis- This is where the cell forms vesicles, and solute will be trapped in those vesicles and moved into the cell. This is also called “cell drinking”!!!

35. B) Exocytosis- Refers to material moving out of the cell i) Removal of waste products from the cell ii) Hormones being released by the cell iii) Neurotransmitters released by axons of nerve cells Proteins in a cell membrane can also assist in getting material across a membrane!!!

36. Introduction to Microbes 1674-Leeuwenhock took pond water and observed “Lots of Wee Animalcules”, He was the first to describe and draw “Microorganisms”! Microbes/Microorganisms-Any form of life that humans can not see with the naked eye! Bacteria- Some bacteria are so small it would take about 17,000 lined up end to end, to equal the diameter of a dime! Bacteria are prokaryotic organisms! The average Eukaryotic cell is 100X larger than a prokaryotic organism! Eukaryotic cells have a nucleus! Prokaryotic organisms have no nucleus! There are about 2-3 million bacteria living on each square centimeter of your skin!

37. Every shovel full of dirt contains more bacteria than all of the Humans that have ever lived on the face of the Earth! Only 1% of all bacteria are know to be pathogens (harmful to other organisms), 99% of bacteria are not harmful or they might be helpful in some way! Bacteria can be used to make medicines, make beverages, make foods Bacteria have the following characteristics: See the board: Nucleoid region DNA and RNA material Ribosomes Cytoplasm Cell membrane Cell wall Capsule Flagella Fimbriae Pili/sex pili

38. Bacterial shapes Bacteria are identified by 3 major shapes: • Coccus (cocci)- Round or sphere shaped Occurs as single organism or in pairs or chains 2) Rod (Bacillus)- Rod shaped Occurs as single organism or in pairs 3) Spirillum- Spiral shaped Occurs as a single organism

39. Bacteria can also be identified by their role in the environment: • Producer- Bacteria that can transform sunlight into energy. These bacteria can be used as food source for other organisms that are not able to make their own food. Ex- Cyanobacteria….Chloroplasts! 2) Decomposers- Get their own energy by breaking down material in dead or decaying organisms. Decomposers help other organisms reuse or recycle materials. Ex- Leaves or dead wood is broken down into materials that can be used by other organisms! 3) Parasites- Bacteria, and other organisms may live on or inside another organism. These relationships may be mutually beneficial, have no effect to one or either individual, or in some cases the host organism may be hurt by the relationship, and this is where the bacteria might be considered the parasite!