General Biology: Scientific Investigation and Biochemistry Study Guide (Video)

FLASHCARDS covering steps of scientific investigation, experimental design, Pasteur’s experiment, biochemistry basics, and macromolecules.

What is the correct order of the five steps of an experiment: observe and state the problem or question; gather info and form a hypothesis; experiment and record results; analyze data and draw conclusions; review and publish results?

1) Observe and state the problem or question; 2) Gather info and form a hypothesis; 3) Experiment and record results; 4) Analyze data and draw conclusions; 5) Review and publish results.

What is a control group in an experiment?

The group that does not receive the experimental treatment and is used for comparison.

What is the dependent variable in an experiment?

The data that is measured.

What is the independent variable in an experiment?

The variable deliberately changed or tested.

What are constants in an experiment?

Factors kept the same in all groups.

What is a hypothesis in scientific investigation?

A proposed explanation for a scientific observation.

What is qualitative data?

Descriptive data (non-numeric observations).

What is quantitative data?

Numeric data (measurable data).

What was Pasteur's hypothesis in his microbial experiment?

That bacteria come from dust particles, not from spontaneous generation.

What were constants in Pasteur’s experiment?

The broth, the environment, and other conditions kept the same in both flasks.

What was the control group in Pasteur’s experiment?

The flask with the intact S-shaped lid (not broken).

What was the independent variable in Pasteur’s experiment?

Whether the flask lid was broken or intact (air exposure).

What was the dependent variable in Pasteur’s experiment?

Bacterial growth in the broth.

What would Pasteur need to do to make the experiment valid?

Ensure only the lid status varies while all other factors are held constant; replicate the experiment.

What is considered the best source of valid and current scientific information?

Peer-reviewed journals and reputable scientific sources.

List the characteristics of living things.

Cellular organization; metabolism; homeostasis; growth; reproduction; response to stimuli; adaptation/evolution; and heredity (DNA).

What is homeostasis?

Maintaining a stable internal environment despite changes outside the organism.

What is the correct order of levels of organization for living things (including cells and organs)?

Atoms → Molecules → Organelles → Cells → Tissues → Organs → Organ systems → Organism.

Name the three subatomic particles, their charges, and their locations in an atom.

Proton: positive charge, located in the nucleus; Neutron: neutral charge, located in the nucleus; Electron: negative charge, located in electron shells/electron cloud.

What is an isotope?

An atom of the same element with a different number of neutrons (and thus different mass).

How can an isotope become radioactive?

If its nucleus is unstable, it can decay by emitting radiation to become more stable.

How do compounds form?

Through chemical bonding between atoms to form molecules.

What is an ionic bond?

A bond formed by transfer of electrons, creating positively and negatively charged ions that attract each other.

What is an ion?

An atom with a net electric charge due to gain or loss of electrons.

What makes an ion positive or negative, and how does this happen?

Losing electrons makes a positive ion (cation); gaining electrons makes a negative ion (anion.)

What is a covalent bond?

A bond formed by sharing electrons between atoms.

Briefly describe Van Der Waals forces.

Weak intermolecular attractions due to temporary dipoles between molecules.

Rank the bonds/attractions from weakest to strongest: covalent bonds, hydrogen bonds, ionic bonds.

Hydrogen bonds < covalent bonds < ionic bonds.

What atoms make up a water molecule, and how many of each atom are there?

Two hydrogen atoms and one oxygen atom (H2O).

What is polarity?

An uneven distribution of electrons leading to partial charges within a molecule.

How does a water molecule form a hydrogen bond with another water molecule? Include which part of one molecule attracts which part of another.

The slightly positive hydrogen in one water molecule is attracted to the lone pairs on the oxygen of another water molecule, forming a hydrogen bond.

What property of water causes water molecules to be attracted to other water molecules?

Cohesion (hydrogen bonding between water molecules).

What property of water causes water molecules to be attracted to other polar molecules?

Polarity leads to adhesion to other polar molecules (and cohesion within water).

Describe how a paper clip can float on water. Which property of water allows this?

If placed gently, surface tension (a result of cohesion) can support the paper clip on the water surface.

Describe how capillary action works. What property of water causes this to happen?

Capillary action occurs due to adhesion of water to a surface and cohesion within water; together they pull water up narrow tubes.

Know the pH scale and where acids, bases, and water are found.

pH scale ranges 0-14; acids < 7, bases > 7, water ~ 7 (neutral).

What are the six main elements that make up all living organisms?

Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, Sulfur (CHNOPS).

What is special about carbon? Hint: Think about its structure.

Carbon can form four covalent bonds (tetravalent) and create long chains and complex structures.

What does the term “organic” mean?

Carbon-containing compounds; typically derived from living organisms.

Fill in the macromolecule chart: Carbohydrates – Monomer; Elements; Function; Examples.

Monomer: monosaccharides; Elements: C, H, O; Function: quick energy and storage; Examples: glucose, starch, cellulose.

Lipids – Monomer; Elements; Function; Examples.

Monomer: glycerol and fatty acids (not a single true monomer); Elements: C, H, O (and P in some lipids); Function: store energy, form membranes; Examples: fats, oils, phospholipids.

Proteins – Monomer; Elements; Function; Examples.

Monomer: amino acids; Elements: C, H, O, N (and S in some); Function: enzymes, structure, transport; Examples: enzymes, collagen.

Nucleic Acids – Monomer; Elements; Function; Examples.

Monomer: nucleotides; Elements: C, H, O, N, P; Function: store and transmit genetic information; Examples: DNA, RNA.

In the given equation 6CO2 + 6H2O → C6H12O6 + 6CO2, which are the reactants and which are the products?

Reactants: 6CO2 and 6H2O; Products: C6H12O6 and 6CO2.

What is an enzyme made of?

Protein.

What is the function of an enzyme?

To catalyze (speed up) chemical reactions by lowering activation energy.

How does an enzyme work? What does it do to a reaction?

An enzyme binds to its substrate at the active site, forming an enzyme–substrate complex and lowering the activation energy to convert substrate to product.

Describe the three factors that can affect an enzyme’s ability to catalyze a reaction.

Temperature, pH, and substrate concentration (and presence of inhibitors/regulators).