Biology Unit 1 Study Guide 2024

Study Notes

Introduction to Biology

Seven characteristics of life include:
- Cellular organization: Living organisms consist of one or more cells.
- Reproduction: Ability to produce new individuals of the same species.
- Metabolism: Chemical processes that sustain life.
- Homeostasis: Maintenance of a stable internal environment.
- Heredity: Transmission of genetic material to offspring.
- Response to stimuli: Detection and reaction to environmental changes.
- Growth and development: Organisms increase in size and undergo development over time.

Scientific Method

Steps include:
- Identifying a problem.
- Formulating a hypothesis.
- Identifying variables.
- Testing the hypothesis.
- Collecting data.
- Analyzing data.

Types of Data

Quantitative: Numerical data that can be measured.
Qualitative: Descriptive data that can be observed.

Analyzing Data

Common methods: Bar and line graphs.

Biochemistry

Subatomic particles:
- Protons: Positive charge, located in the nucleus.
- Neutrons: No charge, located in the nucleus.
- Electrons: Negative charge, found around the nucleus.
Isotopes can become radioactive when their nuclei fail to hold subatomic particles, leading to decay.
Compounds form through interactions of valence electrons between two or more elements.
Ions:
- Charged elements.
- Gaining an electron results in a negative charge.
- Losing an electron results in a positive charge.

Forces and Bonds

Van der Waals forces: Weak electrostatic attractions easily broken.
Hydrogen bonds occur when oxygen and hydrogen atoms of different water molecules attract each other.

Cohesion and Adhesion

Cohesion: Rain droplets merge due to attractive forces.
Adhesion: Rain on a car windshield illustrates how water sticks to surfaces.

Surface Tension

Property allowing objects like a paper clip to float on water due to strong hydrogen bonds creating a thin film.

Capillary Action

Occurs when liquid moves upward due to attractive forces between liquid molecules and solid surfaces (e.g., water climbing a tube/paper towel).

Essential Elements for Life

Six main elements: Sulfur, Phosphorus, Oxygen, Nitrogen, Carbon, Hydrogen (SPONCH).

Carbon's Unique Structure

Carbon has four valence electrons enabling it to form stable bonds with four different atoms.

Polymer Formation

Monomers combine through polymerization, forming larger molecules called polymers.

Chemical Reactions

In chemical equations, reactants are substances transformed in the reaction, while products are resulting substances (e.g., 6CO2 + 6H2O → C6H12O6 + 6O2).

Endothermic vs. Exothermic

Endothermic reactions absorb heat; exothermic reactions release heat.
Graphically, endothermic reactions show heat absorption, while exothermic reactions illustrate energy release.

Function of Enzymes

Enzymes act as natural catalysts speeding up chemical reactions by binding substrates at their active sites.

Enzyme Influencing Factors

pH levels: Changes can denature enzymes.
Temperature: Extreme deviations can also denature enzymes.

Acids, Bases, and Neutral Substances

Acids: Excess of H+ ions.
Bases: Excess of OH- ions.
Neutral: Equal concentrations of H+ and OH- ions.

Macromolecule Metabolism

Dehydration synthesis: A reaction that joins molecules by removing water.

Description

This quiz covers the vital concepts introduced in Unit 1 of Biology, focusing on the seven characteristics of life. Understand how cellular organization, reproduction, metabolism, homeostasis, heredity, and response to stimuli define living organisms. Prepare to master these foundational concepts essential for your biological studies.