Bio study guide 5-6

Energy

The capacity to do work or cause change.

Work

The transfer of energy to an object, causing the object to move.

Bioenergetics

The study of how energy flows through living organisms.

Thermodynamics

The study of energy transformations.

ATP (Adenosine Triphosphate)

The primary energy carrier in cells.

Electromagnetic Spectrum

The range of all types of electromagnetic radiation, including visible light.

Kinetic energy

Energy of motion.

Potential energy

Stored energy due to position or structure.

Heat energy (thermal energy)

A type of kinetic energy from molecular movement.

Light energy

Kinetic energy in the form of electromagnetic radiation.

Chemical energy

Potential energy stored in molecular bonds.

First law of thermodynamics

Energy cannot be created or destroyed, only transformed.

Second law of thermodynamics

Energy transfer increases entropy (disorder), with some energy lost as heat.

ATP

Adenosine triphosphate, contains three phosphate groups, provides energy.

ADP

Adenosine diphosphate, contains two phosphate groups, lower energy form.

ATP conversion to ADP

ATP releases energy when its third phosphate group is removed.

Photosynthesis equation

6CO₂ + 6H₂O + light → C₆H₁₂O₆ + 6O₂

Photo reaction

Converts light energy into chemical energy.

Synthesis reaction

Uses chemical energy to synthesize glucose.

Chloroplast purpose

Chloroplasts house thylakoids, grana, and stroma for photosynthesis.

Visible light & electromagnetic spectrum

Objects appear colored due to reflected wavelengths.

Short vs. long wavelength energy

Shorter wavelengths (blue) carry more energy than longer wavelengths (red).

Pigments

Absorb light for photosynthesis.

Chlorophyll

Absorbs red/blue light and reflects green.

Aerobic Cellular Respiration equation

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + ATP

Glycolysis

The breakdown of glucose into pyruvate.

Oxygen requirement for Glycolysis

Anaerobic (does not require oxygen).

Location of Glycolysis

Cytoplasm.

Inputs of Glycolysis

Glucose, ATP.

Outputs of Glycolysis

Pyruvate, ATP, NADH.

Phases of Glycolysis

Energy investment phase, energy payoff phase.

Energy investment phase

The initial phase of cellular respiration where energy is consumed.

Energy payoff phase

The phase of cellular respiration where energy is produced.

ATP

Adenosine triphosphate, the primary energy carrier in cells.

NADH

Nicotinamide adenine dinucleotide, an electron carrier involved in cellular respiration.

Citric Acid Cycle

A series of chemical reactions used by all aerobic organisms to generate energy.

Location of Citric Acid Cycle

Mitochondria.

Pre-step of Citric Acid Cycle

Pyruvate is converted to Acetyl-CoA.

General outcomes of Citric Acid Cycle

CO₂ release, ATP production, electron carriers (NADH, FADH₂).

Electron Transport Chain

A series of protein complexes that transfer electrons and pump protons to generate ATP.

Location of Electron Transport Chain

Inner mitochondrial membrane.

Kinetic to potential energy conversion

Electron movement powers ATP production.

ATP yield from glucose

~36 ATP per glucose molecule.

Mitochondria and aging

Mitochondrial efficiency declines with age, leading to energy deficits.

Cyanide poisoning

Cyanide blocks electron transfer, preventing ATP production.

Anaerobic respiration

A type of respiration that occurs without oxygen.

Products of anaerobic respiration in animals

Lactic acid.

Products of anaerobic respiration in yeast

Ethanol + CO₂.

ATP yield from anaerobic respiration

2 ATP per glucose.

Chromosome

A DNA molecule containing genetic material.

Genome

The complete set of genetic material in an organism.

Gene

A segment of DNA coding for a protein.

Location of DNA in eukaryotes

Nucleus.

Location of DNA in prokaryotes

Nucleoid region.

Function of DNA

Stores genetic information.

Discovery of DNA structure

Watson & Crick (double helix model).

Structure of DNA

Double-stranded helix with nucleotide pairs (A-T, G-C).

X-ray crystallography

Rosalind Franklin's work contributed to Watson & Crick's model.

Chromosome structure in prokaryotes

Circular chromosomes.

Chromosome structure in eukaryotes

Linear chromosomes.

Genome size vs complexity

No direct correlation.

Coding DNA

Contains genes that code for proteins.

Noncoding DNA

Regulatory sequences, introns, and other non-gene regions.

mRNA

Carries genetic instructions from DNA to ribosomes.

tRNA

Brings amino acids to ribosomes for protein synthesis.

Differences from DNA

Single-stranded, ribose sugar, uracil replaces thymine.

Transcription

DNA → RNA.

Steps of Transcription

Initiation, elongation, termination.

Translation

RNA → Protein.

Codon

Found on mRNA.

Anticodon

Found on tRNA.

Amino acids

Linked into polypeptides.

Steps of Translation

Initiation, elongation, termination.

Gene expression vs gene regulation

The process of converting DNA to RNA and protein versus controlling that process.

Transcription factors

Proteins that influence RNA transcription.

Positive vs negative control

Positive enhances transcription; negative represses it.

Mutations

Changes in DNA sequence.

Causes of mutations

Errors in replication, environmental factors.

Effects of mutations

Positive, neutral, or negative (neutral is most common).

Point mutations

Silent, missense, nonsense.

Chromosomal aberrations

Deletions, duplications, inversions, translocations.