Biology Chapter 2 Flashcards

Questions and Answers

What is Chapter 2 about?

Marine Biology

Human Anatomy

The Biology of Plants

The Chemistry of Life (correct)

Which of the following is NOT one of the six elements that make up the majority of living organisms?

Potassium (correct)

Hydrogen

Oxygen

Carbon

What do atoms contain?

Negatively charged electrons

What is the charge of an atom as a whole?

Neutral Signup and view all the answers

What forms when atoms gain or lose electrons?

Ions Signup and view all the answers

What do Carbon-12 and Carbon-14 have in common?

They have the same number of protons but different numbers of neutrons. Signup and view all the answers

What type of bond do sodium and chlorine form?

Ionic bond Signup and view all the answers

What type of bond exists between carbon and hydrogens in CH4?

Covalent bond Signup and view all the answers

What rule states that 8 electrons in the valence shell make an atom stable?

Octet rule Signup and view all the answers

What type of lipid registers a 5 on the pH scale?

Acid Signup and view all the answers

What is the most acidic solution?

pH of 1 Signup and view all the answers

In a glass of lemonade, what is sugar considered?

Solute Signup and view all the answers

What must molecules contain to be classified as organic?

Carbon Signup and view all the answers

What carbon-based molecule stores genetic information?

Nucleic acids Signup and view all the answers

What are types of lipids?

All of the above Signup and view all the answers

What two types of organic molecules mainly function as an energy source for living organisms?

Lipids and carbohydrates Signup and view all the answers

When do atoms in molecules share pairs of electrons?

When they make covalent bonds Signup and view all the answers

What type of bond forms when a metal transfers one or more electrons to a non-metal?

Ionic bond Signup and view all the answers

What is a weak attraction between slightly positive hydrogen atoms and slightly negative atoms called?

Hydrogen bond Signup and view all the answers

What is the attraction between molecules of the same substance called?

Cohesion Signup and view all the answers

What measures acidity related to the free hydrogen ion concentration in a solution?

pH Signup and view all the answers

What is the general name for a large, carbon-based molecule formed by monomers?

Polymer Signup and view all the answers

What are the four main types of carbon-based molecules?

Carbs, lipids, proteins, nucleic acids Signup and view all the answers

Match the following polymers with their respective macromolecules: Triglyceride, RNA, Enzymes, Cellulose.

Macromolecule: Lipid, Nucleic Acid, Protein, Carbohydrate Signup and view all the answers

What are the monomers of Triglyceride, RNA, Enzymes, and Cellulose?

Fatty Acid, Monosaccharide, Nucleotide, Amino Acid Signup and view all the answers

What does it mean when we refer to Bacteria as prokaryotes?

They are unicellular and their DNA is not contained in a nucleus. Signup and view all the answers

In addition to bacteria, what is the other domain of life that consists of prokaryotes?

Archaea Signup and view all the answers

Which one is not one of the three domains of life?

Protista Signup and view all the answers

What is the shape of rod-shaped bacteria called?

Bacilli Signup and view all the answers

What are spherical bacteria called?

Cocci Signup and view all the answers

What are worm-like bacteria called?

Spirilla Signup and view all the answers

What is a small, circular piece of genetic information inside a bacterial cell called?

Plasmid Signup and view all the answers

How do prokaryotes move?

By the use of flagella Signup and view all the answers

What type of reproduction do bacteria use?

Asexual reproduction Signup and view all the answers

What is the process through which bacteria multiply rapidly known as?

Exponential growth Signup and view all the answers

What is any disease-causing microorganism called?

Pathogen Signup and view all the answers

Who discovered Penicillin, the first antibiotic ever used by humans?

Alexander Fleming Signup and view all the answers

How do antibiotics kill bacteria?

By interfering with their cell wall Signup and view all the answers

What do antibiotics fight?

Bacterial infections Signup and view all the answers

What temperature range is considered the danger zone for bacterial growth?

40-140°F Signup and view all the answers

What process kills bacteria by breaking down their cell walls?

Cooking Signup and view all the answers

What process slows down the bacteria's metabolism and growth?

Chilling Signup and view all the answers

What is the process of using heat to destroy microorganisms called?

Pasteurization Signup and view all the answers

What are some pasteurized foods?

Milk, orange juice, and eggs Signup and view all the answers

What are the 5 steps food takes to get to us?

<ol> <li>Farm, 2. Processing, 3. Transportation, 4. Retail, 5. Your table</li> </ol> Signup and view all the answers

How do bacteria benefit from living in a human digestive system?

They get food (nutrients) and a place to live Signup and view all the answers

Of the thousands of types of bacteria, how many cause disease?

A small fraction Signup and view all the answers

Are all strains of E. coli pathogenic?

Not all Signup and view all the answers

Besides milk, how many types of food are pasteurized?

More than 1,000 Signup and view all the answers

Why are bacteria important?

<ol> <li>Nitrogen fixation, 2. Recycle nutrients, 3. Used to make foods and medicines</li> </ol> Signup and view all the answers

How do antibiotics kill plant cells?

By attacking their cell walls Signup and view all the answers

Why does milk spoil at room temperature?

It is in the danger zone; bacteria thrive in moist environments Signup and view all the answers

What is a solvent?

Water Signup and view all the answers

What is a solute?

Sugar dye in a glass of lemonade Signup and view all the answers

What is a solution?

The stirred-up mixture Signup and view all the answers

What pH levels are considered acidic?

Anything below 7 Signup and view all the answers

Study Notes

The Chemistry of Life

Key elements in living organisms include carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur; potassium is not a major component.
Atoms consist of negatively charged electrons, positively charged protons, and neutral neutrons; when protons and electrons are equal, the overall charge is neutral.
Ions are formed through the gain or loss of electrons by atoms.

Isotopes and Bonds

Carbon-12 and carbon-14 are isotopes distinguished by different neutron counts while maintaining the same proton number.
Sodium and chlorine form ionic bonds through the transfer of electrons, while carbon and hydrogen in CH4 are connected by covalent bonds.

pH and Acidity

An octet of eight electrons in the valence shell confers stability on an atom.
Solutions with a pH of 1 are considered the most acidic, and acidic substances have pH values below 7.
In lemonade, sugar acts as the solute which dissolves in water, the solvent, creating a solution.

Organic Molecules

Organic molecules must contain carbon.
Nucleic acids are carbon-based molecules that store genetic information; they include DNA and RNA.
Lipids, including fats, oils, and cholesterol, function as energy sources along with carbohydrates.

Molecular Structures

Polymers, which consist of large carbon-based molecules formed from monomers, include triglycerides, RNA, enzymes, and cellulose.
Monomers encompass fatty acids, monosaccharides, nucleotides, and amino acids contributing to the structure of respective polymers.

Prokaryotes and Bacteria

Bacteria, classified as prokaryotes, are unicellular organisms whose DNA is not enclosed in a nucleus; archaea represent another domain of prokaryotes.
Bacteria exhibit various shapes: bacilli (rod-shaped), cocci (spherical), and spirilla (worm-like), while "flagelli" is not a recognized shape.

Genetic Information and Reproduction

Plasmids are small, circular DNA structures within bacterial cells, which can replicate independently of chromosomal DNA.
Bacteria utilize flagella for movement and reproduce asexually through binary fission, allowing rapid population increases known as exponential growth.

Pathogens and Antibiotics

Pathogens are microorganisms that cause diseases; only a small fraction of bacterial species are pathogenic.
Alexander Fleming discovered penicillin, the first antibiotic, which disrupts bacterial cell walls, effectively targeting bacterial infections.

Food Safety and Bacteria

The danger zone for bacterial growth is between temperatures of 40°F and 140°F.
Cooking can kill bacteria by destroying their cell walls and enzymes, while chilling slows bacterial metabolism and growth.
Pasteurization uses heat to eliminate disease-causing microorganisms and is applied to items like milk, orange juice, and eggs.

Role of Bacteria

Most bacteria in the human digestive system provide nutritional benefits and habitat, contributing to processes such as nitrogen fixation and nutrient recycling.
Although many bacteria inhabit the digestive system, only a small subset is harmful, with not all strains of E. coli being pathogenic.
Beyond milk, numerous other types of food undergo pasteurization to ensure safety.

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Test your knowledge on the chemistry of life with these flashcards for Biology Chapter 2. Each card contains key terms and definitions vital for understanding the basics of biological chemistry. Perfect for review and exam preparation.