Unit Test

• Animal Cells

  • No cell wall, only a plasma membrane
  • No chloroplast present
  • Vacuoles are not present or are small
  • Contain centrioles within a centrosome area
  • Without a cell wall
  • Cell is flexible with a round shape
  • Does not have plastids
• Plant Cells

  • Cell wall and plasma membrane present
  • Chloroplast present
  • Large central vacuole present
  • Do not contain centrioles with a centrosome area
  • Cell has a fixed, angular shape (due to rigid cell wall)
  • Have plastids
• Plasma Membrane/Cell Membrane

  • Controls the movement of substances
  • Composed of phosphlipids
  • Partially permeable (allows things to pass through it)
• Cytoplasm

  • Fluid filled space containing dissolved substances, enzymes, and organelles
• Cytoskeleton

  • Gives structure
  • Network of fibers (microfilaments) extending throughout the cytoplasm
• Nucleus (control center)

  • Brain of the cell
  • Contains genetic information in the form of chromosomes <- made of DNA
• Mitochondria

  • In plants and animals
  • Has a double membrane
  • Uses glucose to make chemical energy (ATP) t power the cell's biochemical reactions
• Ribosomes

  • Produce protein
  • Appears as dark granules in the cytoplasm
  • Site of protein synthesis (e.g. enzymes)
• Rough Endoplasmic Reticulum (rER)

  • Consists of flattened membrane sacs
  • Located near the nucleus
  • Ribosomes attached to rER <- why it's rough
  • Synthesizes proteins
  • rER in muscles are involved in muscle contraction
• Smooth Endoplasmic Reticulum

  • No ribosomes present
  • Involved with synthesis of steroids and lipids
• Golgi Apparatus (Golgi Body)

  • Consists of flattened membrane sacs
  • Processes (modifies) + distributes proteins from rER, lipids from smooth ER and other substances (shipping center)
  • Repackages proteins in vesicles for secretion outside the cell
  • Secretes mucus
• Plant Cells have the same organelles as animal cells except for;

  • Flagella <- Movement
  • Cilia <- Movement
  • Centrioles <- Mitosis
  • Lysosomes<- Chemicals that break down
• Vacuoles

  • Single membrane with fluid inside
  • Stores ions and nutrients
  • Contains enzymes that break down macromolecules and cell wastes
  • In plant cells, vacuoles are large and permanent (Central vacuole)
  • In animal cells, vacuoles are small and temporary'
• Cell Wall (Only in plant cells)

  • Around the cell membrane
  • Walls consist mainly of cellulose
• Cellulose

  • Permeable - does not affect transport in and out of cell
  • Strong - gives support to the cell and prevents the plasma membrane bursting
  • Hard to digest - Resistant to being broken down
  • Lasts a long time without need for replacement
• Chloroplasts

  • Found only in plant cells
  • Involved in photosynthesis
  • Contains chlorophyll (pigment that makes stuff green)
  • Absorbs light energy and uses it to produce glucose <- photosynthesis
• Cell Cycle Phases:

  1. Interphase
  2. Mitosis
  3. Cytokinesis
• Mitosis Phases:

  1. Prophase
  2. Metaphase
  3. Anaphase
  4. Telophase
• Interphase

  
• Prophase

  
• Metaphase

  
• Anaphase

  
• Telophase

  
• Cytokinesis

  
• Tumours: Abnormal growth of tissue
• Benign Tumours:

  • Non-cancerous
  • Encapsulated and only put pressure on surrounding tissue
  • Easy for remove
• Malignant Tumours:

  • Considered cancerous
  • Not encapsulated
  • Difficult to remove
  • Interfere with the function of neighbouring cells which eventually lead to organ failure
• Metastasis: Process of cancer cells breaking away from the primary tumour and establishing another secondary tumour elsewhere in the body
• Stem Cells:

  • Unspecialized cells that can continuously divide and replicate
  • Have the capacity to differentiate into specialized cell types
• Differentiation/Cell Specialization

  • Process during development where newly formed cells become more specialized and distinct from one another as they mature
  • Each cell contains the entire set of genetic instructions (DNA) for that organism
  • Activation of different instructions (genes) within a given cell by chemical signals will activate the differentiation
• Levels of Specialization:

  • Totipotent: Can differentiate into any type of cell (all)
  • Pluripotent: Can differentiate into many types of cell (not all)
  • Multipotent: Can differentiate into a few closely related types of cells (few)
  • Unipotent: Can regenerate but can only differentiate into their associated cell type (one)
• Types of Stem Cells

  • Embryonic stem cells can differentiate into any kind of cell
  • Tissue stem cells exist within specialized tissue (bone marrow). Only able to differentiate into certain types of cells
• Purpose of the Digestive System: Break down large molecules into smaller subunits for absorption
• Stem Cell Sources:

  • Embryo
  • Cord Blood
  • Adult
• Embryo

  • Ease of extractions: Can be obtained from excess embryos generated by IVF programs
  • Ethics of Extraction: Can only be obtained by destruction of an embryo
  • Growth potential: Almost unlimited
  • Tumour Risk: Higher risk of development
• Umbilical Cord Blood

  • Ease of extractions: Easily obtained and stored (limited quantities available)
  • Ethics of Extraction: Cord removed at birth and discarded whether or not stem cells are harvested
  • Growth potential: Reduced potential
  • Tumour Risk: Lower risk of development
• Adult

  • Ease of extractions: Difficult to obtain (very few and are buried deep in tissues)
  • Ethics of Extraction: Adult patient can give permission for cells to be extracted
  • Growth potential: Reduced potential
  • Tumour Risk: Lower risk of development
• Digestion: Food is broken down both physically and chemically
• Absorption: Digested food products are absorbed into the bloodstream and transported to cells
• Assimilation: Digested food products are converted into the fluid and solid parts of a cell/tissue