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Cytology. Cytology. Cytology : study of the structure and function of cells. Cytoplasm : area of space outside the nucleus; contains the organelles & cytosol. Organelles are tiny structures in the cytoplasm which perform various jobs for the cell.
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Cytology • Cytology : study of the structure and function of cells. • Cytoplasm : area of space outside the nucleus; contains the organelles & cytosol. • Organelles are tiny structures in the cytoplasm which perform various jobs for the cell. • Cytosol is the fluid part of the cytoplasm.
Prokaryotic Cells • They lack a nuclear membrane as well any other membrane covered organelles in their cytoplasm. • Considered to be “Primitive Cells” • Example : Bacteria & Blue-Green Algae
Eukaryotic Cells • They possess a nuclear membrane as well as membrane bound organelles in their cytoplasm. • Example : Plant & Animal Cells
The Nucleus • is the computer or control center of the cell. • discovered by James Watson, Francis Crick, & Rosalind Franklin (1953). • contains the genetic material of life DNA (Deoxyribonucleic acid). • a DNA molecule consists of nucleotides connected together.
Nucleotide A nucleotide consists of a : 1. Phosphate group 2. Deoxyribose sugar 3. Nitrogen base: 4 types Adenine (A) Thymine (T) Cytosine (C) Guanine (G) DNA consists of two nucleotide chains connected together. A & T always pair up, while C & G do the same.
DNA Replication New Strand Original strand Nitrogen Bases Growth Growth Replication Fork Replication Fork DNA Polymerase
Long chains of DNA form Chromatin. • Short sections of DNA along a piece of chromatin form Genes. • A gene will either produce or influence a specific trait in the offspring.
Chromatin Chromatin Nucleosome DNA double helix Coils Supercoils Histones
Nucleolus / Nucleoli (plural) : a dark spherical structure that is the site of ribosome formation. • Ribosomes and other important chemical messages leave the nucleus through the Nuclear Pores. The membrane around the nucleus is called the Nuclear Membrane or Envelope.
Mitochondrion • Mitochondria (plural) : is a membrane bound oval shaped organelle that function as the cell’s “power plant”. • Creates the energy rich molecule called ATP (Adenosine Triphosphate). • ATP is created through a process called Cellular Respiration which requires oxygen and therefore is an Aerobic process
Cellular Respiration C6H12O6 + 6O2 + enzyme 6CO2 + 6H2O + 36 ATP Only eukaryotic cells have mitochondria. The Cristae (inner membrane with finger-like projections) have enzymes attached to them where cellular respiration occurs. Mitochondria have their own DNA different from that of the nucleus. Biologists believe that a bacteria got trapped inside the early cell and evolved into this energy producing organelle. This mitochondrial DNA is very similar to bacterial DNA !
How do prokaryotic cells make ATP? • They rely on a process called Fermentation. • Fermentation is a simple Anaerobic (no O2) process that partially breaks down glucose to make SOME ATP. • Example: Lactic Acid Fermentation which bacteria and humans perform. Glucose + Enzyme Lactic Acid + 2 ATP
Chloroplast • Found only in plant cells. • Contain the green pigment chlorophyll. • They are involved with the process of Photosynthesis which takes place within these Thylakoid Membranes.
Photosynthesis 6CO2 + 6H2O + sun light C6H12O6 + 6O2 The glucose created from photosynthesis can now be broken down through Cellular Respiration to make 36 ATP. Chloroplasts also have their own DNA ?
Plant Cell Nucleolus Nucleus Smooth endoplasmic reticulum Nuclear envelope Ribosome (free) Rough endoplasmic reticulum Ribosome (attached) Cell wall Golgi apparatus Cell membrane Chloroplast Mitochondrion Vacuole
Animal Cell Smooth endoplasmic reticulum Nucleolus Nucleus Ribosome (free) Nuclear envelope Cell membrane Rough endoplasmic reticulum Ribosome (attached) Centrioles Golgi apparatus Mitochondrion
Plant & Animal CellSimulation • Click on the title above and work through the plant and animal cell simulation.
Animal Cell Matching Activity • Click on the title above and it will lead you to the animal cell website. • Click on the “start activity” icon and let the fun start!