Nature of Science Overview

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Questions and Answers

What is the dependent variable in the experiment studying how much water a plant species gets on its growth?

pH of the soil

The amount of water

Temperature

Growth (correct)

Cell theory states that all living organisms are made up of cells.

True

Explain how a source of scientific error is different from a mistake.

A source of scientific error refers to systematic errors that can affect results consistently, while a mistake is often a random error due to human oversight or miscalculation.

The ________ is responsible for protein synthesis in eukaryotic cells.

ribosome Signup and view all the answers

Match the following organelles to their functions:

Nucleus = Control center of the cell Mitochondria = Energy production Golgi Apparatus = Protein modification and sorting Lysosome = Digestion of waste Signup and view all the answers

What happens if we decrease the surface area to volume ratio of our cells?

Decreased efficiency of waste removal Signup and view all the answers

All cells contain a nucleus.

False Signup and view all the answers

What is the function of cholesterol in the cell membrane?

Cholesterol helps to stabilize the cell membrane and maintain its fluidity, especially in varying temperatures. Signup and view all the answers

What term describes a solution with a lower solute concentration compared to another solution?

Hypotonic solution Signup and view all the answers

Osmosis involves the movement of solute molecules through a semipermeable membrane.

False Signup and view all the answers

Define passive transport.

The movement of substances across a cell membrane without the use of energy. Signup and view all the answers

In cellular respiration, glucose is broken down to produce ______ as a main energy currency for cells.

ATP Signup and view all the answers

Match the following terms with their correct definitions:

Hydrophilic = Attracted to water Hydrophobic = Repellent to water Polar = Molecules with a partial positive and negative charge Nonpolar = Molecules that do not have charged regions Signup and view all the answers

Which statement best describes the fluid mosaic model of the cell membrane?

The membrane consists of a double layer of phospholipids with embedded proteins. Signup and view all the answers

Condensation reactions involve the breaking down of larger molecules into smaller ones.

False Signup and view all the answers

What does it mean to denature a protein?

To disrupt the protein's structure, rendering it nonfunctional. Signup and view all the answers

During photosynthesis, light energy is converted into chemical energy stored in ______.

glucose Signup and view all the answers

Which of the following processes requires energy input?

Active transport Signup and view all the answers

Study Notes

Nature of Science

The scientific method generally involves observation, forming a hypothesis, experimentation, analyzing data, and drawing conclusions.
A theory is a well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experimentation. A hypothesis is a testable prediction about the relationship between two or more variables. A theory is broader, supported by evidence while a hypothesis is a proposed explanation often focused on a specific situation.
A source of scientific error is a flaw in the design, execution, or analysis of an experiment that can affect the results, while a mistake is a simple error in carrying out the work. Bias or a poorly controlled variable could be an example of a source of error.
Mean: average of a data set. Mode: most frequent value. Median: middle value when data is ordered.
Standard deviation measures the spread of data around the mean, providing a more comprehensive understanding of data distribution than just the mean.
Error bars on a graph visually represent the uncertainty or variability in data points. They are typically created using the standard deviation or standard error, and can be used to see if there are overlaps in data ranges.

Chapter 1: Cell Biology

1.1 - Introduction to Cells
- Dependent variable in plant growth experiment: Plant growth.
- Cell theory: All living things are made of cells; cells are the basic units of life; cells arise from pre-existing cells.
- Small cell size maximizes surface area-to-volume ratio, enabling efficient exchange of materials. Reduced surface area-to-volume ratio would hinder efficient exchange of materials and limit a cell's ability to function.
- Prokaryotes lack membrane-bound organelles. Eukaryotes have membrane-bound organelles.
- Functions of life: Responding to stimuli, growth, reproduction, nutrition, metabolism, excretion, homeostasis.
- Cell size calculation involves dividing the drawing size by the magnification.
- Estimate cell size by measuring the cell's length and width, converting micrometers to millimeters, considering microscope magnification.
1.2 - Ultrastructure of Cells
- Organelle Function Definitions: (These are very general and require further study)
Cytoplasm: Fluid inside the cell.
Ribosomes: Protein synthesis
Nucleus: Control center
Rough endoplasmic reticulum: Protein synthesis and modification.
Smooth endoplasmic reticulum: Lipid synthesis and detoxification.
Golgi apparatus: Modifies, sorts, and packages proteins.
Lysosomes: Digestion.
Mitochondria: Energy production (ATP).
Chloroplast: Photosynthesis.
Vacuoles: Storage
Vesicles: Transport
Microtubules: Cell structure
Centrioles: Cell division.
Cilia: Movement.
Flagella: Movement.
1.3 - Membrane Structure
- Cholesterol maintains membrane fluidity.
- Membrane proteins provide transport, recognition, and enzymatic activity.
- Phospholipid amphipathic nature (both hydrophilic and hydrophobic) creates the cell membrane structure.
1.4 - Membrane Transport
- A solution with 10% sugar compared to a solution with 3% sugar will cause the 10% sugar solution to be hypertonic (higher concentration), causing solvent movement from the lower concentration of solution 3%.
- Everyday diffusion: Perfume spreading in a room.
- Passive transport: Movement of substances based on concentration gradients (no energy required). Example: diffusion.
- Active transport: Movement of substances against concentration gradients (requires energy). Example: protein pumps
- Osmosis: Movement of water molecules across a semipermeable membrane. Example: Water moving into root cells.
- A potato that gains mass was in a hypotonic solution; a potato that lost mass was placed in a hypertonic solution. Higher solute concentration, or molarity, in one solution would be associated with the solution whose opposite result appears in the experiment. (For example, if a potato gains mass, the opposite would be that the solution lost mass.
- Hypotonic: lower solute concentration, Hypertonic: higher solute concentration, Isotonic: equal solute concentration.
- Honeycrisp apple is in a hypertonic solution at approx. 10%.

Chapter 2: Molecular Biology

2.2 - Water
Adhesion: Water molecules' ability to stick to other substances. High adhesion of water to plant tissue aids in water transport.
Cohesion: Water molecules' attraction to each other. This high cohesion is why water is a liquid at room temperature.
Surface tension: Water's resistance to breaking at the liquid–air interface. Allows small insects to walk on water.
Specific heat: Water's high capacity to store heat. Moderates temperature changes in organisms. These properties are all linked to the polarity of the water molecule which makes it a powerful solvent.
Hydrogen bonds form between water molecules due to the dipole nature of water - because of the polar qualities. This shapes water's properties and how it interacts with molecules around it.
hydrophilic: likes water (polar) ; hydrophobic: dislikes water (nonpolar).
2.1 - Molecules to Metabolism
- Carbon is versatile due to its ability to form four covalent bonds.
- Monomer: single unit (e.g., glucose) ; Polymer: chain of monomers (e.g., starch).
2.3 - Carbohydrates and Lipids
- Carbohydrates: Energy storage, structural support.
- Lipids: Energy storage, insulation, cell membranes.
- Saturated fatty acids have single bonds between carbon atoms; unsaturated fatty acids have one or more double bonds. Trans fats are generally viewed as less healthy than their cis counterparts.
Condensation/dehydration synthesis: joining monomers to form polymers with the removal of water ; Hydrolysis: breaking polymers into monomers with the addition of water.
- Cellulose, starch, and glycogen are polysaccharides composed of glucose and differ in their structure and function.
2.4 - Proteins
- Amino acids form proteins
- Some examples of protein structure and function: Hemoglobin carries oxygen, while collagen provides structural support.
- Primary (sequence), Secondary (folding-alpha helix and beta sheet), Tertiary (3D shape), Quaternary (multiple separate proteins joined to form larger structure).
Protein structure depends on amino acid properties; protein alteration occurs from differing interactions and types of amino acids.
- Denaturing a protein changes its shape and it loses its function.
- Peptide bonds form from a condensation reaction between amino acids.
2.5 - Enzymes
- Substrate: reactants acted upon by an enzyme.
- Product: result of the enzyme-catalyzed reaction.
- Enzyme function is affected by pH, temperature, and substrate/enzyme concentration. Denaturing changes the active site, rendering it nonfunctional.
- Enzymes are catalysts, not reactants or products, they speed up the process without being consumed themselves.
Chapter 2: Cellular Respiration and Photosynthesis
- 2.8 Cell Respiration
  - Chemical equation: C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + ATP. (Reactants: glucose and oxygen) (Products: carbon dioxide, water and ATP).
  - ATP: Energy currency of the cell, fuels a vast series of functions throughout an organism's cellular systems and processes.
  - Aerobic: Oxygen required, greater energy yield, occurs in mitochondria (e.g., Krebs cycle, electron transport chain). Anaerobic: Oxygen not required, lesser energy yield, occurs in cytoplasm (e.g., fermentation).
- 2.9 Photosynthesis
  - Photosynthesis: Energy from the sunlight, converts light energy into chemical energy, and occurs in plants and some other organisms.
    - Chemical equation: 6CO₂ + 6H₂O + light energy → C₆H₁₂O₆ + 6O₂. (Reactants: Carbon dioxide and water) (Products: glucose and oxygen).
  - The bulk of a tree's mass comes from the carbon in the carbon dioxide absorbed from the atmosphere.
Chapter 2: DNA and Protein Synthesis
- 2.6 DNA & RNA
  - Nucleotide components: 5-carbon sugar, phosphate group, nitrogenous base.
  - DNA: double helix; RNA: single-stranded; both carry genetic information, but RNA is more involved in protein synthesis.
- 2.7 Replication, Transcription, Translation
  - DNA replication is semiconservative meaning that each new DNA molecule is half original and half new.
  - Replication: DNA to DNA for cell division;
  - Transcription: DNA to RNA for protein production;
  - Translation: RNA to proteins.
  - Structural Differences: mRNA carries genetic information; rRNA forms ribosomes; tRNA brings amino acids to the ribosome.
  - Codons: mRNA sequences encoding amino acids; anticodons: tRNA sequences complementary to codons. - Transcription and translation: (sequence based).

Chapter 6: Human Digestive System

Digestive system organs and their functions will have to be added by student/group/person. (Organ parts and functions should be included.)

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Description

This quiz covers the fundamental concepts of the nature of science, including the scientific method, theories vs. hypotheses, and common sources of scientific error. It also addresses statistical measures such as mean, mode, median, and standard deviation. Test your understanding of these essential scientific principles.