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Introduction to Cells Cells are the basic units of organisms

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1 Introduction to Cells Cells are the basic units of organisms
Cells can only be observed under microscope Basic types of cells: Bacterial Cell Animal Cell Plant Cell

2 Number of Cells Organisms may be: Unicellular – composed of one cell
Multicellular- composed of many cells that may organize

3 Cells May be Prokaryotic or Eukaryotic
Prokaryotes: include bacteria & lack a nucleus or membrane-bound structures called organelles Eukaryotes: include most other cells & have a nucleus and membrane-bound organelles (plants, fungi, & animals)

4 Prokaryote vs Eukaryote
Two structural types of cells are recognized: Prokaryotic Archaea and bacteria Eukaryotic: plants, algae, fungi, protists, and animals (variety) Comparing prokaryotic and eukaryotic cells Prokaryote comes from the Greek words for prenucleus. Eukaryote comes from the Greek words for true nucleus.

5 Prokaryote Eukaryote Contains plasma membrane Contains plasma membrane
Simpler internal structure Absence of nucleus One circular chromosome, not in a membrane No membrane enclosed organelles Peptidoglycan cell walls Binary fission for cell division Smaller Contains plasma membrane Contain nucleus Paired chromosomes, in nuclear membrane Membrane enclosed organelles Simple (polysaccharide) cell walls Cell division by mitosis or meiosis Larger

6 Structure of Prokaryotic vs. Eukaryotic cell

7 Prokaryotes – The first Cells
Cells that lack a nucleus or membrane-bound organelles Includes bacteria Simplest type of cell Single, circular chromosome copyright cmassengale

8 Prokaryotes Nucleoid region (center) contains the DNA
Surrounded by cell membrane & cell wall (peptidoglycan) Contain ribosomes (no membrane) in their cytoplasm to make proteins copyright cmassengale

9 Eukaryotes Cells that HAVE a nucleus and membrane-bound organelles
Includes protists, fungi, plants, and animals More complex type of cells copyright cmassengale

10 Differences b/w the 2 types of cells
Eukaryotic Prokaryotic Larger Contains membrane bound organelles Contains a nucleus Smaller Does not contain membrane bound organelles No nucleus

11 a large central vacuole plants plasma membrane prokaryotes
Words you can use: Animals bacteria chloroplasts Eukaryotes a large central vacuole plants plasma membrane prokaryotes All cells have a: And are grouped into two broad categories: Which are mainly: Some contain yeast and algae Which contains unique structures such as: Cell walls

12 a large central vacuole plants plasma membrane prokaryotes
Words you can use: Animals bacteria chloroplasts Eukaryotes a large central vacuole plants plasma membrane prokaryotes All cells have a: Plasma membrane And are grouped into two broad categories: prokaryotes eukaryotic Which are mainly: bacteria plants animals Some contain yeast and algae Which contains unique structures such as: Cell walls chloroplasts A large central vacuole

13 Viruses Non cellular Obligate intracellular parasites
They must live inside another cell to survive Have only one type of nucleic acid DNA or RNA (never both) Single or Double stranded Protein coat (no plasma membrane) Few to no enzymes Takes enzymes and use host cell metabolic machinery No metabolic activity They require a host cell to exhibit the characteristics of life. Virus diversity Different viruses have different hosts Only some viruses cause disease

14 Structure & Organelles Vocabulary
Plasma Membrane Cytoskeleton Nucleus Nucleolus Golgi Apparatus Endoplasmic Reticulum Chloroplast Mitochondria Lysosome Vacuole Vesicle Cell wall Ribosome Cytosol Cytoplasm

15 Organelles Very small (Microscopic) “little organs” that carry out specific functions within each cell Perform various functions for a cell Found in the cytoplasm May or may not be membrane-bound

16 Eukaryotic: Animal Cell

17 Eukaryotic: Plant Cell

18 Prokaryotic Cell

19 Plasma Membrane (AKA cell membrane
Function: A flexible boundary that controls the movement of substances in and out of the cell. Key word: Selective permeability. Cell Type: All cells Analogy: __________

20 Cell Membrane in Plants
Lies immediately against the cell wall in plant cells Pushes out against the cell wall to maintain cell shape

21 Cell Wall Nonliving layer Found in plants, fungi, & bacteria
Made of cellulose in plants Made of peptidoglycan in bacteria Made of chitin in Fungi Cell Type: Plants Analogy:_____________________________

22 Cell Wall Supports and protects cell
Found outside of the cell membrane

23 More on Cytoplasm Contains organelles to carry out specific jobs
Collective term for cytosol plus the organelles suspended within the cytosol Found in ALL cells Analogy:______________________

24 Cytosol The fluid surrounding the cytoplasm’s organelles, internal membranes, and cytoskeleton fibers Analogy:_______________________ copyright cmassengale

25 Cytoskeleton Helps cell maintain cell shape and supporting structure
Also help move organelles around Made of proteins Microfilaments are threadlike & made of ACTIN Microtubules are tubelike & made of TUBULIN Analogy:____________________________

26

27 Cellular Support Cytoskeleton is made of microtubules thin, hollow cylinders made of protein, & microfilamentsthin solid protein fibers

28 Cytoskeleton MICROTUBULES MICROFILAMENTS copyright cmassengale

29 Nucleus Function: The nucleus contains the cells DNA, stores information used to make proteins For cell growth, function & reproduction. Key Word: Control Center Cell Type: All Eukaryotic Cells Analogy: ____________

30 Nucleolus Inside nucleus Cell may have 1 to 3 nucleoli
Disappears when cell divides Makes ribosomes that make proteins Analogy:____________________ copyright cmassengale

31 Endoplasmic Reticulum - ER
Network of hollow membrane tubules Connects to nuclear envelope & cell membrane Functions in Synthesis of cell products & Transport Analogy?_________________________________ Two kinds of ER ---ROUGH & SMOOTH copyright cmassengale

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

33 Smooth Endoplasmic Reticulum
Smooth ER lacks ribosomes on its surface Is attached to the ends of rough ER Makes cell products that are USED INSIDE the cell copyright cmassengale

34 Functions of the Smooth ER
Makes membrane lipids (steroids) Regulates calcium (muscle cells) Destroys toxic substances (Liver) copyright cmassengale

35  Ribosomes “Protein factories” for cell
Small particles of RNA and protein found throughout the cytoplasm. Produce proteins by following coded instructions that come from the nucleus. Join amino acids to make proteins Process called protein synthesis Analogy:________ copyright cmassengale

36 Golgi Apparatus Function: It’s a flattened stack of membranes that modifies, sorts & packages proteins into sacs. Key Word: Packing & Sorting Cell Type: All Eukaryotic Cells Analogy: ____________

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

38 Golgi copyright cmassengale

39 Vesicles -small saclike organelles that store and transport materials around the inside of cells copyright cmassengale

40 Chloroplasts Function: Capture light energy & convert it into chemical energy through photosynthesis. Key Word: Producer of energy Cell Type: Euk. Plant cell Analogy: ____________

41 Vacuoles Fluid filled sacks for storage
Small or absent in animal cells Plant cells have a large Central Vacuole No vacuoles in bacterial cells Analogy:_______________ copyright cmassengale

42 Vacuoles In plants, they store Cell Sap
Includes storage of sugars, proteins, minerals, lipids, wastes, salts, water, and enzymes copyright cmassengale

43 Mitochondria Function: It converts fuel particles (mainly sugar) into usable energy. Key Word: Powerhouse Cell Type: All Eukaryotic Cells Analogy: ____________

44 MITOCHONDRIA CONT Has its own DNA Surrounded by a DOUBLE membrane
Folded inner membrane called CRISTAE (increases surface area for more chemical Reactions) Interior called MATRIX copyright cmassengale

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

46 Lysosomes Function: Processes enzymes that digest excess or worn out organelles, wastes. Key Word: Gets rid of waste Cell Type: Euk. Animal Cells Analogy: ____________

47 Similarities between plant cells and animal cells
Both have a cell membrane surrounding the cytoplasm Both have a nucleus Both contain mitochondria

48 Differences between plant cells and animal cells
Relatively smaller in size Relatively larger in size Irregular shape Regular shape No cell wall Cell wall present

49 Differences between Plant Cells and Animal Cells
Vacuole small or absent Large central vacuole Glycogen as food storage Starch as food storage Nucleus at the center Nucleus near cell wall

50 Cell Movement with Cilia & Flagella
copyright cmassengale

51 Cilia & Flagella Cilia short, numerous, hair-like projections that move in a wavelike motion

52 Flagella larger projections that move w/ a whip-like motion

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

54 Cilia Moving Away Dust Particles from the Lungs Respiratory System
copyright cmassengale

55 Cell Size Question: Are the cells in an elephant bigger, smaller, or about the same size as those in a mouse? copyright cmassengale

56 Cell Size Question: Are the cells in an elephant bigger, smaller, or about the same size as those in a mouse? About the same size, but … The elephant has MANY MORE cells than a mouse! copyright cmassengale


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