Comprehensive Biology Notes

Animal Cell Structures

Golgi Vesicle: Membrane-bound vesicles involved in transporting and processing proteins and lipids.
Mitochondria: Organelles with a double membrane (outer smooth membrane and inner membrane with cristae) responsible for energy production via the degradation of organic molecules.
Golgi Apparatus: Stacks of flattened sacs or vesicles continuous with the smooth endoplasmic reticulum (SER) channels; involved in storing, modifying, and packaging materials for secretory export.
Ribosomes: Involved in active protein synthesis.
Nucleoli: Structures within the nucleus involved in ribosome biogenesis; composed of RNA, DNA, and protein; synthesize rRNA and assemble ribosomal subunits.
Chromatin: A complex of DNA and proteins in the nucleus responsible for packaging DNA into a compact structure, enabling effective gene regulation and expression.
Pinocytic Passage: A specific type of endocytosis where cells engulf extracellular fluid and dissolved substances, allowing nutrient and molecule uptake.
Cytoplasm: The region surrounding the nucleus and enclosed by the cell membrane; the site of metabolism, transport, and support within the cell.
Pinocytic Vesicle: A small membrane-bound structure formed during pinocytosis, allowing cells to take in extracellular fluid and dissolved substances.
Fat Vacuole: A reservoir for lipids that stores energy, maintains cell turgor, and contributes to cellular metabolism.
Nucleus: An organelle surrounded by a double membrane (nuclear membrane or envelope).
Rough Endoplasmic Reticulum: Associated with active protein synthesis.
Smooth Endoplasmic Reticulum: Involved in the synthesis and transport of lipids and the detoxification of various poisons.
Secretion Vesicle of Golgi Apparatus: Mediates the vesicular transport of cargo.
Centrioles: Play a role in the formation of the spindle apparatus, essential in mitosis and meiosis.
Plasma Membrane: The outer layer of the living cell; controls the passage of materials into and out of the cell; separates and protects the cell's interior, regulates substance movement, facilitates communication via receptor proteins, and provides structural support.
Lysosomes: Contain powerful enzymes that digest cellular content if not contained within the impermeable lysosomal membrane; play a role in intracellular digestion.

Plant Cell Structures

Nuclear Envelope: The double membrane surrounding the nucleus.
Central Vacuole: A large vacuole in plant cells that can act as a reservoir for fluids and salts.
Peroxisome: Contains oxidative enzymes involved in the oxidative degradation of amino acids.
Cell Wall: Provides support to plant cells and prevents bursting.
Smooth ER: Endoplasmic reticulum without ribosomes on its surface. Functions include lipid and steroid synthesis, carbohydrate metabolism, and detoxification of drugs and poisons.
Lysosome: Contains enzymes that break down cellular waste and debris. In plants, they are less prominent than in animal cells but are still involved in degradation processes.
Golgi Apparatus Processes and packages proteins and lipids, then sends them to other organelles or outside the cell.
Mitochondria Site of cellular respiration, which converts glucose (sugar) into ATP (energy) in both plant and animal cells.
Chloroplasts Site of photosynthesis, capturing light energy to convert carbon dioxide and water into glucose and oxygen. This is a key difference between plant and animal cells.
Plasmodesmata: Microscopic channels traversing plant cell walls, enabling transport and communication between cells.
Nucleus Stores cell's genetic material and controls cell activity.
Nucleolus Forms ribosomes.

Organelles Unique to Plants

Cell Wall: Provides support and turgor.
Chloroplasts: Site of photosynthesis; absent in animal cells.

Common Organelles in Plants and Animals

Mitochondria
Nucleus
Lysosomes

Laboratory One: Measures and Statistics

Introduction: Biological phenomena exhibit variation. To apply scientific analysis, parameters of interest must be quantified. Statistics is used to assess biological variation and describe relationships among biological parameters.
Statistical Assumptions:
- Objects measured are randomly selected and independent.
- Variation fits a normal curve.
- Numbers used are gained by measuring.
Statistical Techniques: Derive numerical values compared to standardized distributions to make statements about the likelihood that observed variation is not merely random but due to some cause.
Experiment Setup:
- Leaves collected from the top surface and deep inside a shrub.
- Each person collects two leaves, removes them with stems attached, then detaches the leaf from the stem.
- Leaves are weighed to the nearest one-thousandth of a gram.
- Surface area approximated using the formula: $(\frac{major\ axis}{2})(\frac{minor\ axis}{2})(\pi) = area$

Chi-Square Analysis

Chi-square ( $x^2$ ) test is used to measure the association between variables and perform a probability-of-occurrence analysis.
Formula: $x^2 = \sum \frac{(O-E)^2}{E}$ , where O is observed value and E is expected value.
Degrees of freedom for a 2 x 2 table = 1.
Probability threshold: p < 0.05.
Critical value: 3.84.
In the experiment, the hypothesis was that leaves from the exterior would be bigger due to sunlight exposure.
For both mass and area, the $x^2$ value was calculated to be 1.06.
Since 1.06 < 3.84, the groups were not significantly different by mass or area.
The hypothesis was not supported.
Area is considered a better parameter for determining the difference in leaf size due to sunlight exposure because more surface area means more sun exposure.

Probability and Correlation

Probabilities are represented by values from 0-1 (0 = never happen, 1 = must happen).
Probability of Event A = number of successes / number of trials.
The experiment included observations of Whitetip Reef Sharks (Triaenodon obesus) in reef and seagrass bed areas.
Correlation between number of sharks observed and the two sites was calculated.
- Reef area correlation: 0.945 (very strong positive relationship)
- Seagrass bed correlation: -0.008 (negligible relationship)
August was identified as the best month for seeing whitetip reef sharks because the probability was the highest.

Laboratory Three: Literature Review and Presentation

Literature review and research are essential to modern science.
Objective: Conduct a literature review using online resources and databases to examine mainstream media's take on a chosen topic versus peer-reviewed journals.
Topics include controversial scientific subjects with social implications (e.g., clean/unclean foods of various religions). The goal is to determine the empirical nature of the topics.
Presentation: Each group will give a 5-minute presentation on its chosen topic, determining the mainstream idea, and comparing it against peer-reviewed science.

Laboratory Four: Photosynthesis

Photosynthesis is the method by which photoautotrophs produce energy in chloroplasts, known as "primary production."
During photosynthesis, plants convert inorganic carbon (CO2) into organic carbon, with oxygen as a waste product. Aquatic plants absorb dissolved CO2 from the water.
$CO<em>2 + H</em>2O \rightleftharpoons H<em>2CO</em>3$
Bromothymol blue is an indicator that is blue at neutral pH but turns yellow in the presence of acid.
A spectrophotometer measures light absorption/transmission. The greater the concentration of CO2 in the water, the less light is absorbed at 625 nm.

Experiment

Hypothesis: If a plant is exposed to sunlight, photosynthesis will be higher.
Procedure:
- Bromothymol blue is added to water and bubbled until a color change occurs (due to the presence of CO2).
- Aquatic plants are placed in tubes under various conditions (sunlight vs. dark).
- Observations and spectrophotometer readings are recorded.
Observations:
- Plant Tube 1 (P1) in sunlight: Color turned a lighter shade of yellow as CO2 was absorbed.
- No Plant Tube 1 (NP1) in sunlight: No change because no plant was present to absorb CO2.
- No Plant Tube 2 (NP2): No change.
- Plant Tube 2 (P2) in the dark: Solution turned into a darker shade of green because the plant absorbed more CO2, making it less acidic.
Spectrophotometer Results:
- P1 had a higher absorption number than the rest, indicating that the plant absorbed the most CO2.
Analysis:
- The results of the indicator and spectrophotometer tests matched up.
- The spectrophotometer test provided quantitative data, while the indicator test was qualitative.
- The hypothesis was not supported by both tests.
Controls: NP1 and NP2

Cell Component Functions

Cell Membrane: Outer layer of the cell, controls the passage of materials.
Cell Wall: Provides support and prevents bursting.
Rough Endoplasmic Reticulum: Associated with active protein synthesis.
Smooth Endoplasmic Reticulum: Involved in lipid synthesis, transport, and detoxification.
Golgi Apparatus: Storage, modification, and packaging of materials for export.
Golgi Vesicle: Transport and processing of proteins and lipids.
Mitochondria: Energy production via degradation of organic molecules.
Lysosomes: Intracellular digestion.
Peroxisome: Oxidative degradation of amino acids.
Flagella and Cilia: Cell motility.
Centrioles: Spindle apparatus formation during mitosis and meiosis.
Vacuole: Reservoir for fluids and salts.
Chloroplast: Contains pigments or provides storage space for starch.
Nucleus: Enclosed by a double membrane; contains DNA.
Chromatin: DNA and protein complex for packaging DNA, gene regulation, and expression.
Nucleoli: Ribosome biogenesis.
Secretary Vesicle of Golgi Apparatus: Mediates the vesicular transport of cargo.
Fat Vacuole: Reservoir for lipids, energy storage, cell turgor, and metabolism.
Pinocytic Vesicle: Uptake of extracellular fluid and dissolved substances.
Pinocytic Passage: Endocytosis of extracellular fluid and substances.
Cytoplasm: Metabolism, transport, and support within the cell.
Plasma Membrane: Separates and protects the cell, regulates substance movement, facilitates communication, and provides support.
Plasmodesmata: Microscopic channels between plant cells for transport and communication.