Detailed Notes on Cell Biology and Tissues

Exam 1 Review and Class Updates

• Exam 1 Average: 74%

  • Good average considering it's the first exam.
  • Includes extra credit from the Kahoot challenge.
  • Aim is to see this average increase as students adapt to the course format.

• Kahoot Challenge Extra Credit

  • Worth up to an additional 4% on the final grade.
  • Significant impact on grade (e.g., B+ to A-).
  • Encouragement to take advantage of these opportunities.

• Exam Analysis

  • Review of exam performance to identify any issues with the key or questions.
  • No questions were dropped from this exam.

Chemistry Questions Review

• Strongest Bond Type

  • Question: Which of the following is the strongest of all bond types?

  • Correct Answer: Nonpolar covalent.

  • Explanation:

    • Covalent bonds are strong and used in proteins and DNA.
    • Nonpolar covalent bonds have equally distributed electrons, making them stronger than polar covalent bonds.

• Nitrogen Atomic Structure

  • Question: Nitrogen has an atomic number of 7 and an atomic mass of 14. How many neutrons and protons does it have?

  • Explanation:

    • Atomic number = number of protons (ID tag of the atom).
    • Atomic mass = protons + neutrons.
    • Nitrogen has 7 protons and 7 neutrons.

Respondus and Exam Submission

• Incomplete Check Answer

  • In Respondus, leaving answers unchecked may show as incomplete but submissions usually count.
  • Can check answers at the end to avoid anxiety during the test.
  • Checking answers can sometimes provide hints for later questions.

• Free Navigation

  • Tests are designed with free navigation to allow movement between questions, similar to a paper exam.

Memorial Day and Exam Scheduling

• Adjustments for Memorial Day

  • Next Monday is Memorial Day.
  • Proposed solution: Open the exam earlier, from Thursday after class until the start of class the following Tuesday.

Week 2 Labs: Cell Biology and Tissues

• Lab Schedule

  • Week 2 covers cell biology and tissues (Chapters 3 and 4).
  • Materials organized in a logical order corresponding to lectures.
  • Homework assignments have unlimited attempts.
  • Quizzes have one attempt.

• APR (Anatomy and Physiology Revealed)

  • Utilizes animations and cadaver specimens.

• Lab Manual Quizzes

  • Divided into two parts for simplification.
  • Quiz 1 covers questions 1-9 and 15 from Exercise 4.
  • Quiz 2 covers questions 10-14, 16, 19, 31, 32, and 33 from Exercise 4.

• Tissue Assignments

  • Two homework assignments and a web activity.
  • Review questions from the lab manual are part of the homework (unlimited attempts).

Web Activities Review

• Primary Tissue Web Activity

  • Involves watching a three-minute video on the four primary tissues.

• Mitosis Mover Web Activity

  • Provides good practice and is also used in advanced cell and molecular biology courses.

• Lab Submission Deadline

  • Labs are due by 7:00 AM on Mondays.
  • Late submissions are penalized 20% per day.

Chapter 3 Recordings and Review Handout

• Chapter 3 Cell Biology

  • Cell structure and function, internal organelles.

• Chapter 4 Tissues

• Review Handout

  • Review handout to be used as guide, accessible for both Tuesday and Thursday meetings.

Cell Structure and Function

• Cell membrane functions include:

  • Plasma membrane with surface extensions like microvilli, centrosome and centrioles, essential for cell replication during mitosis or cell division.

• Nucleus Function:

  • Houses DNA (chromosomes and genetic material).

• Nucleolus Function:

  • Produces ribosomes.

• Ribosomes:

  • Protein production (translation).

• Mitochondria:

  • Powerhouse of the cell, main source of ATP.

  • ATP, produced via oxidative phosphorylation.

  • Active cells (cardiac & skeletal muscle) have many mitochondria.

• Golgi complex:

  • Sorting station for proteins (post office of the cell).

  • Synthesizes lysosomes, which are organelles filled with hydrolytic enzymes.

• Lysosomes:

  • Filled with hydrolytic enzymes for breaking down substrates (catabolic properties).

• Endoplasmic Reticulum (ER):

  • Rough ER: Associated with ribosomes; functions in protein synthesis.

  • Smooth ER: Lacks ribosomes; synthesizes lipids (steroids like testosterone, estrogen).

• Detoxification:

  • Smooth ER neutralizes toxic materials (pharmaceuticals, recreational drugs, alcohol).

  • Smooth ER makes components of the plasma membrane.

• Plasma Membrane:

  • Outer boundary of cell, synthesized by smooth ER, also referred to as cell membrane.

Plasma Membrane and Transport

• Plasma Membrane Composition

  • Phospholipids:

    • Most abundant component arranged in a bilayer with hydrophilic heads facing outwards and hydrophobic tails facing each other.

Phospholipid Hydrophilic Interaction

    *   Outer leaflets interface with extracellular fluid; inner leaflets interface with intracellular fluid.

• Cholesterol:

  *   Maintains membrane fluidity/flexibility.
  

• Proteins

  • Transmembrane proteins create pathways for transport.

• Carbohydrates

  *   Glycolipids and glycoproteins form the glycocalyx on the outside of the membrane.
  

• Glycocalyx functions:

  • Cell identification, protection, immunity to infection, defense against cancer, transplant compatibility.

  • Blood type is determined through the blood tissue.

Surface Extensions

• Microvilli

  • Shortest extension, for absorption in the GI tract, increasing surface area.

• Cilia

  • Found on all cells, specialized for sensory input (smell, taste, hearing) and motile functions (upper respiratory tract).
  • Movement for the cilia is important for the upper respiratory tract.

• Flagella

  • Longest extension, found only on sperm cells for delivering paternal genetics.

Membrane Transport

Basics

• Semi-Permeable Membrane

  • Regulates movement with two transport types.

Passive Transport

• Movement from high to low concentration (down the concentration gradient).

• No energy required.

  Types include:

  • Filtration: Due to blood pressure in capillaries and kidneys.
  • Diffusion: Water movement (osmosis).
  • Facilitated Diffusion: Requires a carrier protein, still passive.

Active Transport

• Movement from low to high concentration (against the concentration gradient).

• Requires ATP.

Types include:

*   Sodium Potassium Pump:

    *   ATPase requires ATP for sodium and potassium exchange against concentration gradients.

    *   Active transport transports the Sodium Potassium pump.

        *   Na^+ and K^+ ATPase.
*   Endocytosis: Bulk transport into the cell, nonselective, includes:

    Phagocytosis: Cell eating, engulfing intruders (WBC consuming bacteria).
    Pinocytosis: Cell drinking, monitoring extracellular changes, picking up hormones.
    Receptor-Mediated Endocytosis: Lock and key mechanism, e.g., insulin binding to receptors.
*   Exocytosis: Bulk transport out of the cell, nonselective.

Tonicity

• Isotonic: Same solute concentration inside and outside the cell. Net water gain and loss are equal, maintaining cell shape.

• Hypotonic: Lower solute concentration outside the cell. Water moves into the cell, causing swelling or hemolysis (rupture).

• Hypertonic: Higher solute concentration outside the cell. Water moves out of the cell, causing shriveling (crenation).

Gene Expression and Protein Synthesis

• Genetic Code

Information

*   DNA Language: TAC, CGC, CCT, etc.

DNA to RNA Translation

• Transcription

  • DNA to mRNA conversion

  • A
    ightharpoonup U; C
    ightharpoonup G;
    G
    ightharpoonup C;

• Translation:

  • mRNA code translated by ribosomes to assemble proteins, where tRNA delivers correct amino acids (anticodon matches).

Cell Cycle and Mitosis

Cell Cycle Overview

• Interphase
  • G1 Phase: Normal cell functions.
  • S Phase: Duplicates DNA.
  • G2 Phase: Prepares to divide.
• M Phase Mitosis
  • Nuclear Division: PMAT (Prophase, Metaphase, Anaphase, Telophase).
  • Cytoplasmic Division: Cytokinesis.

Mitosis Phases

• Prophase: Chromosomes condense, nucleus breaks down.

• Metaphase: Chromosomes align in the center

• Anaphase: Sister chromatids split

• Telophase: DNA relaxes, nucleus reforms, tidying up.

• Cytokinesis: Cytoplasmic division.

Week 2 Assignments and Schedule

• Watch Chapter 4 lecture (Tissues) with handout.

• Start Week 2 labs.

• Complete extra credit Kahoot challenge (PIN provided).

• Work on the practice worksheet for Exam 2.