Lesson 1 BIOL 1333

Science

A process of using observations and experiments to draw evidence-based conclusions that aims to explain the natural world [1]

Key Properties of Science

Must be reproducible, does not make moral or aesthetic judgments, does not tell you how to use the knowledge [2]

Scientific Method Steps

Observations → Questions → Research of hypotheses → Experimentation → Draw Conclusions [2]

Hypothesis

An explanation for a scientific observation that should be testable and falsifiable; hypotheses are never proven, only supported or refuted by evidence [2][3]

Variables in Experiments

Independent variable is changed/manipulated; dependent variable responds to it; controlled variables are kept identical [4]

Experimental vs. Control Groups

Experimental groups receive treatment/independent variable; control groups receive no treatment or placebo [5]

Statistical Significance

Real results not due to chance; larger sample sizes increase statistical significance [5]

Scientific Theory

Unified insights; a general set of principles supported by evidence that explains some part of nature [5][6]

Five Properties of Organisms

Growth, reproduction, homeostasis, sensing and responding to stimuli, ability to obtain and use energy [7]

Matter and Element

Matter is anything that has mass and takes up space; element is a pure substance that cannot be broken down further [7]

Atomic Structure

Protons (positive), neutrons (neutral), electrons (negative) [7][8]

Organic vs. Inorganic Molecules

Organic molecules have carbon-based backbones and at least one C-H bond; inorganic molecules lack these features [9]

Biological Macromolecules

Carbohydrates, lipids, proteins, nucleic acids [10]

Function of Carbohydrates

Energy storage (quick energy) and structural support (cellulose) [10]

Importance of Protein Shape

Complicated 3D folding creates unique shapes essential to function; incorrect shapes prevent proper function [10][11]

Nucleic Acids Function

Store and execute genetic instructions; made up of nucleotides containing phosphate, sugar, and base [11]

Key Properties of Lipids

Not made of linked monomers; hydrophobic (don't mix well with water); used for energy storage [11]

Phospholipid Bilayer

Cell membranes have two layers; hydrophilic heads face water, hydrophobic tails face inward [12]

Importance of Water to Cells

Site of all life's chemical reactions; comprises 79% of cell's weight; polar molecule with hydrogen bonding [12][13]

pH Measurement

Concentration of hydrogen ions in a solution; acids have low pH with many hydrogen ions; bases have high pH with fewer hydrogen ions [14]