Chemistry of Life - Chapter 2

These flashcards cover the essential concepts and details from Chapter 2 on the Chemistry of Life, providing a comprehensive review for exam preparation.

What is the purpose of the Curiosity rover on Mars?

To explore the surface of Mars and search for evidence of life.

Where did the Curiosity rover land on Mars?

Curiosity safely landed in Gale Crater.

What is the basic structural unit of life?

The cell.

What are the five properties that all living organisms share?

1. Grow 2. Reproduce 3. Maintain homeostasis 4. Sense and respond to stimuli 5. Obtain and use energy.

Define homeostasis.

The maintenance of a relatively constant internal environment.

How do unicellular organisms grow?

By increasing in cell size before reproduction.

How do multicellular organisms grow?

By increasing in size through the increase in the number of cells.

What is reproduction in living organisms?

The process of producing new organisms.

What does it mean for an organism to sense and respond to stimuli?

Organisms can react to various stimuli such as food or threats.

What is metabolism?

The sum total of all chemical reactions that convert energy into usable forms.

What is matter?

Anything that takes up space and has mass.

What are elements?

Substances that cannot be chemically broken down.

Define an atom.

The smallest unit of an element that retains its property.

What is the nucleus of an atom?

The dense core of an atom.

What particles determine the identity of an atom?

Protons, neutrons, and electrons.

What is the charge of electrons?

Negative.

How is the atomic number of an atom determined?

By the number of protons present in the nucleus.

What is the atomic number of carbon?

6.

What is the periodic table?

A table that organizes all known elements by atomic number.

How are elements on the periodic table organized?

By atomic number.

What is a key component of life's molecules?

Carbon.

Percentage of carbon in the human body?

18%.

What type of bonds can carbon form?

Covalent bonds.

What distinguishes organic molecules from inorganic molecules?

Organic molecules contain a carbon backbone and at least one C–H bond.

What are macromolecules?

Large organic molecules composed of subunits called monomers.

What types of macromolecules are essential for life?

Carbohydrates, proteins, lipids, nucleic acids.

What are carbohydrates composed of?

Repeating subunits of simple sugars.

What are proteins made of?

Folded polymers made of amino acids.

What are lipids characterized by?

They are not made of repeated monomers and are hydrophobic.

What are nucleic acids?

Polymers made of repeating nucleotide subunits.

What is a cell?

The basic structural unit of life.

What are cell membranes?

Double layers that separate the cell contents from the environment.

Why is water essential for life?

All life’s chemical reactions take place in water.

What is a polar molecule?

A molecule with unequal sharing of electrons leading to partial positive and negative charges.

What are hydrogen bonds?

Attractions formed between water molecules and other molecules.

List one unique property of water.

Water is less dense as a solid than as a liquid (ice floats).

What is a solvent?

A substance in which another substance dissolves.

What is a solute?

A dissolved substance in a solution.

What helps define acids and bases in solutions?

The concentration of hydrogen ions (H+) in a solution.

What is the pH scale range?

0 to 14.

What is one potential definition of life?

An organism that grows, reproduces, and maintains homeostasis.

Example of a non-living entity that shares some characteristics of life.

Fire can grow, reproduce, and use energy, but it is not considered alive.

Is there liquid water present on the surface of Mars?

No, liquid water is not present on the surface of Mars.

What is one of the driving questions regarding life on Mars?

Could similarly adaptive organisms have once inhabited Mars?

What does it mean for an organism to grow?

An increase in size, either by increasing cell size or by increasing the number of cells.