Biology Chapter on Enzymes
41 Questions
1 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

What does keratin primarily form in the body?

  • Nail and hair structures (correct)
  • Enzymes
  • Bone structures
  • Muscle tissue

Translation occurs in the nucleus.

False (B)

What is the role of mRNA during protein synthesis?

To carry the coded message from DNA to the ribosome.

The process of making mRNA from DNA is called __________.

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

Match the components of protein synthesis to their roles:

<p>DNA = Directs the synthesis of proteins mRNA = Carries the genetic code to ribosomes tRNA = Brings amino acids to the ribosome rRNA = Forms part of the ribosome structure</p> Signup and view all the answers

What is the primary function of enzymes in biological reactions?

<p>To speed up reactions (A)</p> Signup and view all the answers

Enzymes can be used up in a reaction and are therefore not reusable.

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

What structure binds to the enzyme at its active site?

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

Enzymes are most active at an optimum temperature of _____ degrees Celsius in humans.

<p>37</p> Signup and view all the answers

Match the following types of enzyme inhibition with their characteristics:

<p>Competitive inhibition = Molecules similar to the substrate bind blocking the active site Non-competitive inhibition = Binder to allosteric site changes active site shape Allosteric regulation = Substances can inhibit or stimulate enzyme activity</p> Signup and view all the answers

Which of the following describes non-competitive inhibition?

<p>An inhibitor changes the shape of the active site. (B)</p> Signup and view all the answers

Enzymes can exhibit allosteric regulation where certain substances can enhance their activity.

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

Name the two main processes that enzymes are involved in.

<p>building up (condensation) and breaking down (hydrolysis)</p> Signup and view all the answers

Cells control enzyme activity by _____ the production of specific enzymes.

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

What is the primary function of enzymes?

<p>To act as catalysts in chemical reactions (A)</p> Signup and view all the answers

Enzymes change their structure permanently after a chemical reaction.

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

What are the two main types of enzymes?

<p>Endoenzymes and Exoenzymes</p> Signup and view all the answers

Which nitrogenous bases are classified as pyrimidines?

<p>Cytosine and Thymine (C)</p> Signup and view all the answers

The hypothesis that describes how substrates bind to enzymes is known as the __________ hypothesis.

<p>Lock and Key</p> Signup and view all the answers

Match the following terms with their definitions:

<p>Active site = Region where substrates bind Enzyme-substrate complex = Temporary formation between an enzyme and its substrate Induced fit model = Active site is flexible and adjusts to fit substrates Exoenzymes = Enzymes that act outside of the cells</p> Signup and view all the answers

The semiconservative model of DNA replication ensures that each daughter cell receives a complete copy of the original DNA.

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

Which factor does NOT affect enzyme activity?

<p>Color of the enzyme (C)</p> Signup and view all the answers

What is the role of helicase during DNA replication?

<p>To unwind the DNA strands.</p> Signup and view all the answers

Name one example of a chemical reaction that occurs with the help of enzymes.

<p>Photosynthesis or breaking down food</p> Signup and view all the answers

The two strands of DNA run in opposite directions, which is referred to as __________.

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

Match the components of DNA replication with their functions:

<p>DNA polymerase III = Builds new DNA strand RNA Primase = Adds RNA primer Ligase = Joins Okazaki fragments Helicase = Unwinds DNA strands</p> Signup and view all the answers

Which enzyme replaces the RNA primer during DNA replication?

<p>DNA polymerase I (A)</p> Signup and view all the answers

What is the role of allosteric sites in enzymes?

<p>To bind only one substrate, either an activator or a non-competitive inhibitor (C)</p> Signup and view all the answers

The lagging strand is synthesized continuously during DNA replication.

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

An immobilized enzyme allows for repeated use of the same batch.

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

What is the purpose of the single-stranded binding proteins during DNA replication?

<p>To stabilize unwound DNA strands.</p> Signup and view all the answers

Guanine pairs with __________ through triple hydrogen bonds.

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

What is the function of messenger RNA (mRNA)?

<p>To send messages from DNA for protein synthesis.</p> Signup and view all the answers

What is the direction of synthesis for DNA polymerase III?

<p>5' to 3' (A)</p> Signup and view all the answers

DNA stands for __________.

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

Match the following components with their descriptions:

<p>Adenine (A) = Pairs with Thymine (T) Cytosine (C) = Pairs with Guanine (G) Uracil (U) = Found only in RNA Deoxyribose = Sugar in DNA</p> Signup and view all the answers

Which of the following statements about nucleotides is true?

<p>Nucleotides are composed of a phosphate, a sugar, and a nitrogen base. (D)</p> Signup and view all the answers

Cytosine pairs with Thymine in both DNA and RNA.

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

What is the shape of DNA?

<p>Double helix</p> Signup and view all the answers

The primary sugar found in RNA is __________.

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

What benefit does immobilizing enzymes provide in industries?

<p>Prevents product contamination with enzymes (A)</p> Signup and view all the answers

Flashcards

Enzyme Active Site

The specific region of an enzyme where a substrate molecule binds and undergoes a chemical reaction.

Enzyme Substrate

The molecule acted upon by an enzyme.

Lock and Key Model

An outdated model of enzyme action where the enzyme's active site is rigid and perfectly matches the substrate.

Induced Fit Model

The modern model of enzyme action where the enzyme's active site changes shape to better fit and interact with the substrate.

Signup and view all the flashcards

Enzyme function

Enzymes speed up chemical reactions in living things by acting as catalysts.

Signup and view all the flashcards

Enzyme types

Enzymes are categorized into endo- (intracellular) and exo- (extracellular) depending on where they work.

Signup and view all the flashcards

Enzyme activity factors

Temperature, pH, and substrate/enzyme concentration can influence how fast enzymes work.

Signup and view all the flashcards

Enzyme activity optimum temp.

Enzymes work best at a specific temperature, usually 37°C for humans.

Signup and view all the flashcards

Enzyme denaturation

High temperatures cause enzymes to lose their shape and stop working properly.

Signup and view all the flashcards

Active site

The specific region on an enzyme where the substrate binds.

Signup and view all the flashcards

Competitive inhibition

A molecule similar to the substrate blocks the active site, preventing the actual substrate from binding.

Signup and view all the flashcards

Non-competitive inhibition

Inhibitor binds somewhere other than the active site (allosteric site), changing the enzyme's shape.

Signup and view all the flashcards

Allosteric site

A site on an enzyme other than the active site where regulators bind.

Signup and view all the flashcards

Enzyme inhibition (prevent activity)

Cells control enzyme activity to regulate cellular processes. This involves restricting enzyme production or using inhibitors.

Signup and view all the flashcards

Immobilized enzyme

An enzyme whose movement is restricted in space, often attached to a solid structure or incorporated into a gel.

Signup and view all the flashcards

Enzyme immobilization benefits

Multiple uses, rapid reaction stopping, stabilization, product purity, easy separation, multi-enzyme systems, and reduced waste.

Signup and view all the flashcards

DNA

Deoxyribonucleic acid; the genetic material in all living organisms.

Signup and view all the flashcards

Gene

A segment of DNA that codes for a specific trait or protein.

Signup and view all the flashcards

Nucleotide

The basic building block of DNA, composed of a sugar, a phosphate, and a nitrogenous base.

Signup and view all the flashcards

DNA structure

A double helix, with two strands of nucleotides twisted together.

Signup and view all the flashcards

Chargaff's base pair rule

Adenine pairs with Thymine, and Cytosine pairs with Guanine.

Signup and view all the flashcards

RNA

Ribonucleic acid; a single-stranded molecule created from DNA replication, involved in protein synthesis.

Signup and view all the flashcards

Types of RNA

Different types of RNA exist, including mRNA (messenger) and tRNA (transfer), with different roles in protein synthesis.

Signup and view all the flashcards

Protein function

Proteins build structures, carry out cellular processes, and have many other vital roles in an organism.

Signup and view all the flashcards

What is the role of DNA in protein synthesis?

DNA serves as the blueprint, containing the genetic code that specifies the sequence of amino acids in a protein. It acts as the 'director' in the process of protein synthesis.

Signup and view all the flashcards

What are the 3 assistant directors in protein synthesis?

mRNA (messenger RNA), tRNA (transfer RNA), and rRNA (ribosomal RNA) are essential for carrying genetic information and building proteins. They act as the 'assistant directors' in the process of protein synthesis.

Signup and view all the flashcards

What is Transcription?

Transcription is the process of copying genetic information from DNA to mRNA in the nucleus. It's like making a copy of the blueprint before taking it to the construction site.

Signup and view all the flashcards

What happens during Transcription?

DNA unwinds, and the gene's sequence is copied into mRNA. This mRNA molecule then travels out of the nucleus to the cytoplasm.

Signup and view all the flashcards

What is the role of the Ribosome in protein synthesis?

The ribosome serves as the 'stage' where protein synthesis occurs, reading the mRNA instructions and assembling amino acids to create the protein.

Signup and view all the flashcards

Pyrimidine bases

Single-ringed nitrogenous bases found in DNA and RNA. Examples are Cytosine and Thymine.

Signup and view all the flashcards

Purine bases

Double-ringed nitrogenous bases found in DNA and RNA. Examples are Guanine and Adenine.

Signup and view all the flashcards

Base pairing in DNA

Specific hydrogen bonding between complementary nitrogenous bases in DNA: Guanine with Cytosine (triple bond), Adenine with Thymine (double bond).

Signup and view all the flashcards

DNA replication purpose

The process of creating an identical copy of DNA before cell division, ensuring each daughter cell receives a complete set of genetic information.

Signup and view all the flashcards

Semiconservative replication

The model of DNA replication where each new DNA molecule consists of one original strand and one newly synthesized strand. Proven by Meselson and Stahl experiment.

Signup and view all the flashcards

Antiparallel strands in DNA

The two strands of DNA run in opposite directions, with one strand oriented 5' to 3' and the other 3' to 5'.

Signup and view all the flashcards

Helicase enzyme

An enzyme involved in DNA replication that unwinds the double helix, separating the two DNA strands.

Signup and view all the flashcards

RNA Primase

An enzyme that adds a short RNA primer to the 3' end of the template DNA, allowing DNA polymerase III to start building a new strand.

Signup and view all the flashcards

DNA polymerase III

The main enzyme involved in DNA replication, it adds new nucleotides to the 3' end of an existing DNA strand, building a new complementary strand.

Signup and view all the flashcards

Leading strand

The strand of DNA that is synthesized continuously during DNA replication, as it is built in the same direction as the replication fork.

Signup and view all the flashcards

Study Notes

Enzyme Action

  • Enzymes are proteins that act as catalysts, speeding up chemical reactions.
  • Enzymes catalyze one specific reaction.
  • Active site: a region of the enzyme where the substrate binds.
  • Substrate: the molecule that the enzyme acts upon.
  • Enzyme-substrate complex: formed when the substrate binds to the active site.
  • Products: formed when the substrate is broken down or new bonds are formed.
  • Lock and key model: the active site has a rigid shape that perfectly complements the substrate.
  • Induced fit model: the active site changes shape slightly to accommodate the substrate, creating a tighter fit.
  • Enzymes do not get used up in the reaction, they can be reused.
  • Endoenzymes: act within the cells where they are produced (intracellular).
  • Exoenzymes: act outside the cells where they are produced (extracellular).

Factors Affecting Enzyme Activity

  • Temperature: Enzymes work best at specific temperatures.
  • pH: Optimal pH levels exist for enzymes.
  • Substrate concentration: Higher substrate concentration generally leads to faster reaction rates up to a certain point.
  • Enzyme concentration: Higher enzyme concentration generally leads to faster reaction rates up to a certain point.

Enzyme Inhibition

  • Competitive inhibition: a molecule similar to the substrate competes for the active site.
  • Non-competitive inhibition: a molecule binds to a site other than the active site (allosteric site), changing the active site's shape.
  • Allosteric regulation: a molecule called an activator or inhibitor binds to an allosteric site, changing the enzyme's activity.

Immobilized Enzymes

  • Immobilized enzymes are enzymes that are attached to a solid material.
  • This allows for easier separation of products, reuse of the enzyme, and control of reaction conditions.
  • Useful in industrial processes and food production.

DNA

  • DNA makes up genes, which are blueprints for the human body.
  • DNA is made up of nucleotides.
  • Nucleotides are the basic units of DNA.
  • DNA has a double helix shape.
  • DNA is made up of 3 components: a sugar, a phosphate and a nitrogenous base.
  • The rule (Chargaff's base-pair rule): Adenine (A) always pairs with Thymine (T), and Cytosine (C) always pairs with Guanine (G).

RNA

  • RNA is a ribonucleic acid.
  • Created from DNA replication.
  • Single-stranded.
  • RNA has different types including Messenger RNA (mRNA), Transfer RNA (tRNA), and Ribosomal RNA (rRNA).
  • RNA contains a sugar (ribose), a phosphate group, and a nitrogenous base.
  • The nitrogenous bases in RNA are adenine (A), cytosine (C), guanine (G), and uracil (U).

DNA Replication

  • DNA replication is the process of creating an identical copy of a DNA molecule.
  • Semiconservative model: each new DNA molecule contains one original strand and one new strand.

Protein Synthesis

  • Protein synthesis involves two main stages: transcription and translation.
  • Transcription: the process of making mRNA from DNA.
  • Translation: the process of making a polypeptide chain (protein) from mRNA.
  • Proteins are made up of amino acids.
  • The genetic code is used to determine the sequence of amino acids in a protein.

Gene Mutations

  • A mutation is an alteration of the nucleotide sequence of the DNA.
  • Mutations can be helpful, harmful, or neutral.
  • Point mutations: change in one DNA base pair.
  • Frameshift mutations: insertion or deletion of one or more DNA base pairs, shifting the reading frame for subsequent codons.

Genetic Code (codon table)

  • A three-letter sequence of nucleotides (codon) specifies a particular amino acid.

Studying That Suits You

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

Quiz Team

Related Documents

Biology Notes Term 2 PDF

Description

Explore the fascinating world of enzymes in this quiz, focusing on their action, structure, and factors affecting their activity. Test your knowledge on enzyme-substrate interactions, models of enzyme action, and the distinctions between endoenzymes and exoenzymes. Perfect for biology enthusiasts and students alike!

More Like This

Enzyme Action
5 questions

Enzyme Action

CoolSpring avatar
CoolSpring
Mechanism of Enzyme Action: Biochemistry Lecture 3
22 questions

Mechanism of Enzyme Action: Biochemistry Lecture 3

IrresistibleTroll avatar
IrresistibleTroll
Biochemistry Enzyme Action Overview
20 questions

Biochemistry Enzyme Action Overview

EntertainingNephrite1252 avatar
EntertainingNephrite1252
Biochemistry: Enzyme Action & Theories
20 questions

Biochemistry: Enzyme Action & Theories

EntertainingNephrite1252 avatar
EntertainingNephrite1252
Use Quizgecko on...
Browser
Open
Browser
Browser