IB BIO FINAL SEMESTER !

Cellular Respiration

The process by which cells convert glucose and oxygen into energy (ATP), carbon dioxide, and water.

Enzymes

Biological catalysts that speed up chemical reactions in cells by lowering the activation energy required.

Mutations

Changes in the DNA sequence of an organism's genome that can lead to variations in traits.

Gene Editing

A set of technologies that enable the modification of an organism's DNA to achieve desired traits.

Protein Synthesis

The process by which cells create proteins based on the genetic instructions carried by mRNA.

Adaptations to the Environment

Traits or behaviors that enhance an organism's ability to survive and reproduce in its specific environment.

Ecological Niche

The role and position a species has in its environment, including its habitat, resource use, and interactions with other organisms.

Transport

The movement of substances across cell membranes or within organisms, including active and passive transport mechanisms.

Gas Exchange

The process by which oxygen is taken in and carbon dioxide is released, typically occurring in the lungs or gills.

Muscles and Motility

The function of muscles in enabling movement and locomotion in organisms through contraction and relaxation.

What is ATP?

ATP (adenosine triphosphate) is considered the energy currency of the cell because it releases energy quickly for cellular processes.

What is the ATP-ADP cycle?

The ATP-ADP cycle involves the continuous breakdown of ATP to ADP, releasing energy, and the phosphorylation of ADP back to ATP.

What is cellular respiration?

Cellular respiration can be defined as the breakdown of glucose to produce ATP using energy from organic compounds.

How does anaerobic respiration differ from aerobic respiration?

Anaerobic respiration results in the production of lactate in humans and ethanol in yeast, and it does not use oxygen as the final electron acceptor.

Where does the Krebs cycle occur?

The Krebs cycle occurs in the matrix of the mitochondria.

What happens during glycolysis?

During glycolysis, glucose is converted into two molecules of pyruvate, yielding ATP and NADH.

What are NADH and FADH2?

NADH and FADH2 are electron carriers that transfer energy to the electron transport chain.

What is the function of the electron transport chain?

The electron transport chain functions to pump protons (H+) into the intermembrane space, creating a proton gradient.

Why is oxygen essential in aerobic respiration?

Oxygen acts as the terminal electron acceptor in the electron transport chain.

What is chemiosmosis?

Chemiosmosis refers to the production of ATP by ATP synthase as protons flow down their concentration gradient.

What are the main products of anaerobic respiration in yeast?

The main products are ethanol, CO2, and NAD+.

What does the link reaction convert?

The link reaction converts pyruvate to acetyl-CoA with the release of CO2.

What is the main function of the Krebs cycle?

The main function of the Krebs cycle is to generate reduced NADH and FADH2 for the electron transport chain.

Why do lipids yield more energy than carbohydrates in respiration?

Lipids contain more hydrogen atoms that provide electrons for the electron transport chain.

When does anaerobic respiration occur in humans?

Anaerobic respiration occurs when oxygen levels are low, and lactate is produced.

Where are NADH and FADH2 produced?

NADH and FADH2 are produced in the Krebs cycle and glycolysis.

What is the proton gradient used for during respiration?

The proton gradient is used to drive the synthesis of ATP by ATP synthase.

What is the net yield of ATP from glycolysis?

The net yield of ATP from glycolysis is 2 ATP.

What is the formation of lactate during anaerobic respiration?

The formation of lactate regenerates NAD+ to allow glycolysis to continue.

What are the final products of aerobic respiration?

The final products of aerobic respiration are ATP, water, and carbon dioxide.

How do enzymes act as catalysts?

Enzymes act as catalysts by lowering the activation energy needed for a reaction to occur.

What is metabolism?

Metabolism is defined as the sum of all chemical reactions within an organism.

What do anabolic reactions involve?

Anabolic reactions involve the building of larger molecules from smaller ones.

What is the active site of an enzyme?

The active site of an enzyme is flexible and able to change shape to better fit the substrate.

What does the induced fit model propose?

The induced fit model proposes that the active site undergoes a conformational change upon substrate binding.

What does denaturation refer to?

Denaturation refers to a change in the enzyme's structure that leads to the loss of its function.

What is the optimal temperature for enzyme activity in humans?

The optimal temperature for most enzyme activity in humans is 37°C.

What is activation energy?

Activation energy is the energy required to break or weaken bonds in a substrate to start a reaction.

How do competitive inhibitors function?

Competitive inhibitors function by binding reversibly to the enzyme's active site, blocking the substrate.

What occurs during non-competitive inhibition?

Non-competitive inhibition occurs when inhibitors bind to an allosteric site, causing a change in the active site.

What is feedback inhibition?

Feedback inhibition regulates metabolic pathways by preventing the buildup of unnecessary end products.

What are allosteric enzymes?

Allosteric enzymes have multiple binding sites that can be regulated by activators or inhibitors.

How does substrate concentration affect enzyme activity?

Substrate concentration affects enzyme activity by increasing the rate of reaction up to a point where all active sites are saturated.

What are cyclic metabolic pathways?

Cyclic metabolic pathways are pathways that regenerate the initial substrate to continue the cycle.

What do intracellular enzymes do?

Intracellular enzymes catalyze reactions inside the cell where they are synthesized.

What are extracellular enzymes involved in?

Extracellular enzymes are involved in digestive processes outside the cell.

What is the role of heat energy generated by metabolism?

Heat energy generated by metabolism helps birds and mammals maintain body temperature in cold environments.

What is end-product inhibition?

End-product inhibition in the threonine to isoleucine pathway is an example of feedback inhibition.

What is mechanism-based inhibition?

Mechanism-based inhibition occurs when an irreversible chemical change occurs to the enzyme's active site.

What is the primary difference between a base substitution and a deletion mutation?

A base substitution mutation replaces one nucleotide with another, while a deletion mutation removes one or more nucleotides from the DNA sequence.

What does the ATP-ADP cycle involve?

The ATP-ADP cycle involves the release of energy during phosphorylation of ATP.

What happens to glucose during glycolysis?

During glycolysis, glucose is converted into two molecules of pyruvate, yielding ATP and NADH.

What does chemiosmosis refer to?

The process of chemiosmosis refers to the production of ATP by ATP synthase as protons flow down their concentration gradient.

What is the purpose of the proton gradient generated during respiration?

The proton gradient generated during respiration is used to drive the synthesis of ATP by ATP synthase.

What is denaturation in enzymes?

Denaturation refers to a change in the enzyme's structure that leads to the loss of its function.

What is the optimal temperature for most enzyme activity in humans?

The optimal temperature for most enzyme activity in humans is 37°C.

Where do intracellular enzymes catalyze reactions?

Intracellular enzymes catalyze reactions inside the cell where they are synthesized.

What do extracellular enzymes do?

Extracellular enzymes are involved in digestive processes outside the cell.

What occurs during mechanism-based inhibition?

Mechanism-based inhibition occurs when an irreversible chemical change occurs to the enzyme's active site.

What is the formation of lactate in human muscles during anaerobic respiration?

The formation of lactate regenerates NAD+ to allow glycolysis to continue.

What do extracellular enzymes involve?

Extracellular enzymes are involved in digestive processes outside the cell.

What is a substitution mutation?

A mutation that replaces one nucleotide with another in the DNA sequence.

What is a deletion mutation?

A mutation that removes one or more nucleotides from the DNA sequence.

What is a frameshift mutation?

A mutation that results from the insertion or deletion of nucleotides, altering the reading frame of the genetic code.

What is a single-nucleotide polymorphism (SNP)?

A variation of a single base in a DNA sequence that can lead to different traits among individuals.

What ensures the degeneracy of the genetic code?

The presence of multiple codons that can code for the same amino acid.

What is a nonsense mutation?

A mutation that introduces a premature stop codon, leading to a truncated protein.

What is a mutagen?

A chemical or physical agent that induces mutations in DNA.

What causes frameshift mutations?

The insertion or deletion of one or more nucleotides in the DNA sequence.

What distinguishes somatic mutations from germline mutations?

Somatic mutations occur in non-reproductive cells and are not inherited, while germline mutations occur in reproductive cells and can be passed to offspring.

What is a conserved DNA sequence?

A sequence that is maintained across different species due to its evolutionary importance.

What product is commonly encoded by conserved sequences of DNA?

Ribosomal proteins, which are essential for protein synthesis.

Which mutation is most likely to result in sickle cell disease?

A missense mutation in the hemoglobin gene that causes a single amino acid substitution.

What is the role of RNA polymerase in transcription?

To synthesize RNA by using DNA as a template.

Where does translation occur in a eukaryotic cell?

In the ribosome.

What molecule delivers amino acids to the ribosome during translation?

tRNA (transfer RNA).

What is a codon?

A sequence of three nucleotides that codes for one amino acid.

What is the benefit of a degenerate genetic code?

It allows multiple codons to code for the same amino acid, providing redundancy.

What happens during the elongation phase of translation?

tRNA delivers amino acids to the ribosome, which adds them to the growing polypeptide chain.

What is the purpose of alternative splicing?

To allow a single gene to produce multiple protein variants by including or excluding certain exons.

What initiates transcription?

The promoter region of the gene.

What is the function of a proteasome?

To degrade and recycle proteins by breaking them down into amino acids.

What occurs when codon and anticodon pair correctly?

A hydrogen bond forms between the complementary bases.

Which strand does RNA polymerase read during transcription?

The antisense strand of DNA.

Which component binds at the A site of a ribosome?

tRNA with an amino acid.

What mutation results in a stop codon that ends translation prematurely?

A nonsense mutation.

Silent mutation

A mutation that does not change the amino acid sequence of a protein.

Frameshift mutation

A mutation caused by insertions or deletions of nucleotides that shift the reading frame of the genetic code.

Nonsense mutation

A mutation that creates a premature stop codon in the protein sequence, leading to a truncated protein.

Missense mutation

A mutation that results in the substitution of one amino acid for another in a protein.

What is a habitat?

The place where a species, population, or organism lives.

What does adaptation refer to?

A long-term evolutionary change that enhances survival and reproduction.

Marram grass adaptation

Marram grass is adapted to sand dune environments through long, deep roots to stabilize in shifting sands and reduce water loss.

Abiotic variables affecting species distribution

Light, temperature, and soil nutrients.

What is the range of tolerance?

The range of abiotic factors within which an organism can survive and reproduce.

Coral reefs form in waters that are:

Warm, clear, and shallow.

Principal determinants of biome distribution

Temperature and rainfall.

Characteristics of tropical rainforests

High rainfall and consistently warm temperatures.

What is convergent evolution?

When two unrelated species in the same environment evolve to be similar due to similar selective pressures.

Example of convergent evolution

Cacti in North America and euphorbias in Africa both developing adaptations for hot desert environments.