Biology Chapter 2 Flashcards
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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?

<p>Neutral</p> Signup and view all the answers

What forms when atoms gain or lose electrons?

<p>Ions</p> Signup and view all the answers

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

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

What type of bond do sodium and chlorine form?

<p>Ionic bond</p> Signup and view all the answers

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

<p>Covalent bond</p> Signup and view all the answers

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

<p>Octet rule</p> Signup and view all the answers

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

<p>Acid</p> Signup and view all the answers

What is the most acidic solution?

<p>pH of 1</p> Signup and view all the answers

In a glass of lemonade, what is sugar considered?

<p>Solute</p> Signup and view all the answers

What must molecules contain to be classified as organic?

<p>Carbon</p> Signup and view all the answers

What carbon-based molecule stores genetic information?

<p>Nucleic acids</p> Signup and view all the answers

What are types of lipids?

<p>All of the above (D)</p> Signup and view all the answers

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

<p>Lipids and carbohydrates</p> Signup and view all the answers

When do atoms in molecules share pairs of electrons?

<p>When they make covalent bonds</p> Signup and view all the answers

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

<p>Ionic bond</p> Signup and view all the answers

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

<p>Hydrogen bond</p> Signup and view all the answers

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

<p>Cohesion</p> Signup and view all the answers

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

<p>pH</p> Signup and view all the answers

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

<p>Polymer</p> Signup and view all the answers

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

<p>Carbs, lipids, proteins, nucleic acids</p> Signup and view all the answers

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

<p>Macromolecule: Lipid, Nucleic Acid, Protein, Carbohydrate</p> Signup and view all the answers

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

<p>Fatty Acid, Monosaccharide, Nucleotide, Amino Acid</p> Signup and view all the answers

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

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

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

<p>Archaea</p> Signup and view all the answers

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

<p>Protista</p> Signup and view all the answers

What is the shape of rod-shaped bacteria called?

<p>Bacilli</p> Signup and view all the answers

What are spherical bacteria called?

<p>Cocci</p> Signup and view all the answers

What are worm-like bacteria called?

<p>Spirilla</p> Signup and view all the answers

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

<p>Plasmid</p> Signup and view all the answers

How do prokaryotes move?

<p>By the use of flagella</p> Signup and view all the answers

What type of reproduction do bacteria use?

<p>Asexual reproduction</p> Signup and view all the answers

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

<p>Exponential growth</p> Signup and view all the answers

What is any disease-causing microorganism called?

<p>Pathogen</p> Signup and view all the answers

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

<p>Alexander Fleming</p> Signup and view all the answers

How do antibiotics kill bacteria?

<p>By interfering with their cell wall</p> Signup and view all the answers

What do antibiotics fight?

<p>Bacterial infections</p> Signup and view all the answers

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

<p>40-140°F</p> Signup and view all the answers

What process kills bacteria by breaking down their cell walls?

<p>Cooking</p> Signup and view all the answers

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

<p>Chilling</p> Signup and view all the answers

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

<p>Pasteurization</p> Signup and view all the answers

What are some pasteurized foods?

<p>Milk, orange juice, and eggs</p> 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?

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

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

<p>A small fraction</p> Signup and view all the answers

Are all strains of E. coli pathogenic?

<p>Not all</p> Signup and view all the answers

Besides milk, how many types of food are pasteurized?

<p>More than 1,000</p> 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?

<p>By attacking their cell walls</p> Signup and view all the answers

Why does milk spoil at room temperature?

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

What is a solvent?

<p>Water</p> Signup and view all the answers

What is a solute?

<p>Sugar dye in a glass of lemonade</p> Signup and view all the answers

What is a solution?

<p>The stirred-up mixture</p> Signup and view all the answers

What pH levels are considered acidic?

<p>Anything below 7</p> Signup and view all the answers

Flashcards

Key Elements in Life

Carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur are essential for living organisms.

Ions

Ions are charged atoms formed by gaining or losing electrons.

Isotopes

Isotopes are atoms with the same proton number but varied neutron counts.

Ionic Bonds

Ionic bonds form when atoms transfer electrons, like sodium and chlorine.

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Covalent Bonds

Covalent bonds involve the sharing of electrons, seen in molecules like CH4.

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Octet Rule

Atoms are stable when their valence shell has eight electrons.

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pH Scale

The pH scale measures acidity; below 7 is acidic, pH of 1 is the most acidic.

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Solutions

Solutions consist of a solvent and a solute, like sugar in lemonade.

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Organic Molecules

Organic molecules contain carbon and include nucleic acids, lipids, and carbohydrates.

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Nucleic Acids

Nucleic acids like DNA and RNA store genetic information.

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Lipids

Lipids, including fats and oils, serve as energy sources and structural components.

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Polymers

Polymers are large carbon-based molecules formed from monomers.

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Monomers

Monomers are the building blocks of polymers, like amino acids and nucleotides.

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Prokaryotes

Prokaryotes are unicellular organisms, like bacteria, with no nucleus.

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Bacteria Shapes

Bacteria can be bacilli (rod), cocci (spherical), or spirilla (worm-like).

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Plasmids

Plasmids are circular DNA structures in bacteria that replicate independently.

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Flagella

Flagella are tails that help bacteria move.

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Binary Fission

Binary fission is a form of asexual reproduction in bacteria, leading to rapid growth.

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Pathogens

Pathogens are microorganisms that cause diseases; only a few bacteria are pathogenic.

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Antibiotics

Antibiotics, like penicillin, kill bacteria by disrupting cell walls.

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Danger Zone

The danger zone for bacterial growth is between 40°F and 140°F.

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Cooking Bacteria

Cooking kills bacteria by destroying their cell walls and enzymes.

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Chilling Effect

Chilling slows bacterial metabolism and growth.

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Pasteurization

Pasteurization uses heat to kill harmful microorganisms in food and drink.

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Digestive Bacteria

Most bacteria in the digestive system provide nutrients and help processes like nitrogen fixation.

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E. Coli

Not all E. coli strains are harmful; some are beneficial in digestion.

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Food Pasteurization

Many foods undergo pasteurization to eliminate pathogens and ensure safety.

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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.

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