Biology: Proteins, Carbohydrates, and Lipids
45 Questions
5 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which type of protein structure emerges from the interaction of multiple subunits?

  • Quaternary structure (correct)
  • Primary structure
  • Secondary structure
  • Tertiary structure

    • A protein's shape is solely determined by its primary structure and cannot be influenced by temperature changes.

    False (B)

    What types of interactions contribute to the formation of quaternary structure in proteins?

    Hydrophobic interactions, van der Waals forces, ionic attractions, and hydrogen bonds.

    When a protein loses its functional shape due to excessive heat, it is said to be _____

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

    Match the following protein domains with their functions:

    <p>Catalytic domain = Enzyme activity Transmembrane domain = Transport across membranes ATP-binding domain = Energy transfer DNA binding zinc finger domain = Gene regulation</p> Signup and view all the answers

    Which of the following best describes structural isomers?

    <p>They differ in how atoms are joined. (C)</p> Signup and view all the answers

    Cis-trans isomers are identical compounds but differ in orientation around a double bond.

    <p>False (B)</p> Signup and view all the answers

    What type of reactions combine monomers to form polymers by removing a water molecule?

    <p>Condensation reactions</p> Signup and view all the answers

    Proteins are made up of one or more chains of ________.

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

    Which type of isomer is defined as mirror images of one another?

    <p>Optical isomers (B)</p> Signup and view all the answers

    Match the type of reaction with its description:

    <p>Condensation reaction = Energy is used to form bonds and water is released Hydrolysis reaction = Polymers are broken down into monomers and water is consumed</p> Signup and view all the answers

    All macromolecules in organisms are polymers of smaller molecules called monomers.

    <p>False (B)</p> Signup and view all the answers

    What is the pH of pure water?

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

    Which of the following statements about acids is true?

    <p>Weak acids do not completely dissociate in ions. (B)</p> Signup and view all the answers

    Strong acids such as hydrochloric acid can be described as weak acids.

    <p>False (B)</p> Signup and view all the answers

    What is released by acids when they dissolve in water?

    <p>Hydrogen ions (H+)</p> Signup and view all the answers

    A strong base like sodium hydroxide (NaOH) dissociates to release ______ ions.

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

    Match the following compounds with their classification as acids or bases:

    <p>HCl = Strong acid CH3COOH = Weak acid NaOH = Strong base NH3 = Weak base</p> Signup and view all the answers

    Which of the following describes the properties of weak bases?

    <p>They accept H+ ions. (C)</p> Signup and view all the answers

    Ionization of strong acids and bases is reversible.

    <p>False (B)</p> Signup and view all the answers

    What is a characteristic feature of isomers?

    <p>They have the same chemical formula but different arrangements of atoms.</p> Signup and view all the answers

    Which of the following macromolecules are polymers made from smaller molecules called monomers?

    <p>Both A and C (B)</p> Signup and view all the answers

    All macromolecules have the same structure and function.

    <p>False (B)</p> Signup and view all the answers

    What type of bond is formed when electrons are shared equally between atoms?

    <p>Nonpolar covalent bond</p> Signup and view all the answers

    Lipids are defined by their __________ in water.

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

    Match the following macromolecules with their primary components:

    <p>Proteins = Amino acids Carbohydrates = Simple sugars Lipids = Fatty acids and glycerol Nucleic acids = Nucleotides</p> Signup and view all the answers

    What role do functional groups play in macromolecules?

    <p>Influence the chemical properties and reactivity (B)</p> Signup and view all the answers

    Spider silk is composed of carbohydrates.

    <p>False (B)</p> Signup and view all the answers

    Name one practical use of spider silk.

    <p>Medical sutures or biodegradable fishing lines</p> Signup and view all the answers

    What function do chaperones like heat shock proteins serve?

    <p>They assist in folding denatured proteins. (B)</p> Signup and view all the answers

    What is the primary role of cellulose in plants?

    <p>Structural component (A)</p> Signup and view all the answers

    All cells use fructose as an energy source.

    <p>False (B)</p> Signup and view all the answers

    Glycogen serves as the primary storage form of glucose in plants.

    <p>False (B)</p> Signup and view all the answers

    Name the two simple sugars linked by covalent bonds.

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

    What are the two primary types of lipids mentioned?

    <p>Fats and oils</p> Signup and view all the answers

    ____ are modified carbohydrates that contain an amino group.

    <p>Amino sugars</p> Signup and view all the answers

    Monosaccharides are _____ sugars.

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

    Match the following lipids with their roles:

    <p>Fats = Energy storage Phospholipids = Cell membrane structure Chlorophylls = Light energy capture Steroids = Hormones</p> Signup and view all the answers

    Match the following carbohydrate types with their definitions:

    <p>Monosaccharides = Simple sugars Disaccharides = Two simple sugars linked together Oligosaccharides = 3 to 20 monosaccharides Polysaccharides = Hundreds or thousands of monosaccharides</p> Signup and view all the answers

    Which type of fatty acid has no double bonds between carbon atoms?

    <p>Saturated fatty acid (B)</p> Signup and view all the answers

    Which of the following is NOT a type of carbohydrate?

    <p>Amino acids (C)</p> Signup and view all the answers

    Glucose can exist only in a straight chain form.

    <p>False (B)</p> Signup and view all the answers

    Lipids are polar molecules that are soluble in water.

    <p>False (B)</p> Signup and view all the answers

    What are the five-carbon sugars known as?

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

    What type of reaction forms an ester linkage between fatty acids and glycerol?

    <p>Condensation reaction</p> Signup and view all the answers

    Study Notes

    Proteins, Carbohydrates, and Lipids

    •  Macromolecules are large molecules found in living things. Examples include proteins, carbohydrates, lipids, and nucleic acids.
    •  Proteins are polymers of amino acids. They have diverse functions, notably catalyzing reactions (enzymes), providing support, recognizing and responding to non-self substances, controlling physiological processes, carrying substances within the organism, determining gene expression rates, and causing movement.
    •  Proteins are made up of one or more polypeptide chains, which are single, unbranched chains of amino acids.
    •  The 3-dimensional shape of a protein is determined by the sequence of amino acids.
    •  Amino acids have a carboxyl group and an amino group, functioning as both acid and base.
    •  Side chains (R-groups) also have functional groups that affect protein structure and function.
    •  Amino acids are categorized by their side chains.
    •  The alpha carbon is asymmetrical, allowing for different isomers like D- and L-amino acids.
    •  Cysteine has an -SH group that can react with another cysteine side chain to form a disulfide bridge (S-S). These bridges can be important in protein folding, but most cysteines are not involved.
    •  Oligopeptides (peptides) are short polymers of 20 or fewer amino acids.
    •  Polypeptides are longer protein polymers.
    •  Amino acids bond via peptide linkages (peptide bonds), during condensation reactions.
    •  The primary structure of a protein involves the sequence of amino acids. Side chain properties define secondary and tertiary protein structure. The number of possible proteins from the 20 amino acids is substantial.

    Macromolecules and Interactions

    •  Condensation reactions create covalent bonds between monomers to form polymers, releasing a water molecule.
    •  Hydrolysis reactions break down polymers into monomers, consuming a water molecule.

    Carbohydrates

    •  Carbohydrates have the formula (C₁H₂O₁)ₙ. They are sources and transporters of stored energy, and components of many other molecules. They also form extracellular structures like cell walls.
    •  Monosaccharides are simple sugars.
    •  Disaccharides are formed when two simple sugars are linked by covalent bonds.
    •  Oligosaccharides have 3 to 20 monosaccharides.
    •  Polysaccharides have hundreds or thousands of monosaccharides.
    •  All cells use glucose as an energy source in a straight chain or ring form (more stable), which exists as a- or B-glucose, and can interconvert.
    •  Pentoses are five-carbon sugars (e.g., ribose, deoxyribose found in RNA and DNA).
    •  Hexoses are six-carbon sugars (e.g., glucose, fructose, mannose), some of which are structural isomers.
    •  Monosaccharides link via condensation reactions to form glycosidic bonds.
    •  Oligosaccharides are attached to proteins/lipids and function as recognition signals (e.g., ABO blood types).
    •  Polysaccharides are large polymers of monosaccharides linked by glycosidic bonds.
    • Examples are starch (plant glucose storage), glycogen (animal glucose storage), and cellulose (plant structural component).
    •  Carbohydrates are modified via functional group addition, yielding sugar phosphates, amino sugars, and chitin.

    Lipids

    •  Lipids are nonpolar hydrocarbons; insoluble in water.
    •  Weak but additive van der Waals forces hold lipids together in aggregates.
    •  Lipids include fats and oils (store energy), phospholipids (structural role in cell membranes), carotenoids and chlorophylls (capture light energy, Vitamin A), steroids and modified fatty acids (hormones, vitamins), and waxes.
    •  Animal fats provide thermal insulation. Lipid coating around nerves insulates electrically. Oil and waxes on skin/fur/feathers repel water, slowing evaporation.
    •  Fats and oils are triglycerides consisting of three fatty acids and glycerol.
    •  Fatty acids are nonpolar hydrocarbon chains with a polar carboxyl group.
    •  Carboxyls bond with glycerol hydroxyls via ester linkages (condensation reactions).
    •  Saturated fatty acids lack double bonds between carbons, packed tightly (solid).
    •  Unsaturated fatty acids have one or more double bonds between carbons; kinks prevent packing; liquid at room temperature; cis vs trans isomers affect properties.
    •  Polyunsaturated fatty acids have two or more double bonds. Omega-3 fatty acids protect against heart disease.
    •  Phospholipids are similar to triglycerides, but one fatty acid is replaced by a phosphate group, creating a hydrophilic head and hydrophobic tails, these being amphipathic molecules.
    •  Phospholipids form bilayers in water, creating cell membranes.
    •  Lipoproteins in animals transport lipids (e.g., cholesterol) in the blood.
    •  Carotenoids are light-absorbing pigments in plants, converting to Vitamin A in humans.
    •  Steroids have multiple rings and include cholesterol and hormones like estradiol.
    •  Waxes are long-chain alcohols bound to unsaturated fatty acids.

    Protein Structure

    •  Proteins can bind non-covalently to other molecules via shape and chemistry (surface R group interactions via ionic, hydrophobic, or hydrogen bonds) factors.
    •  Denaturation occurs when heat or pH changes disrupt the secondary, tertiary, and quaternary structures of proteins. Some proteins revert to their original structure upon cooling (reversible denaturation). However, sometimes the change is irreversible.
    •  Chaperones (e.g., heat shock proteins) help proteins fold correctly and prevent inappropriate binding.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Proteins, Carbohydrates, and Lipids PDF

    Description

    Explore the fascinating world of macromolecules in this quiz, focusing on proteins, carbohydrates, and lipids. Learn about the structure, function, and importance of proteins made up of amino acids, and understand how their shape influences biological processes.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser