Midterm Study Guide for CPP

How Do Enzymes Work?

  • Enzymes accelerate chemical reactions.

  • They lower the Activation Energy (EA) required for reactions.

  • Example: Without enzymes, the digestion of food would be extremely slow (decades).

What is Metabolism?

  • Metabolism: Total of all chemical reactions in an organism, divided into two categories:

    • Catabolism: Breakdown of molecules to obtain energy (energy produced).

    • Anabolism: Synthesis of larger molecules from smaller ones using energy (energy consumed).

Anabolism

  • Involves joining smaller molecules into larger molecules.

    • Monosaccharides → Polysaccharides

    • Fatty Acids → Triglycerides

    • Amino Acids → Proteins

    • Nucleotides → Nucleic Acids

  • Energy consumption is integral to anabolic processes.

Catabolism

  • Process where larger molecules are broken down into smaller ones.

  • Produces energy:

    • ATP (~40% of energy produced).

    • Heat (~60% of energy produced).

The Production of ATP

  • During catabolic reactions:

    • Proteins → Amino acids

    • Lipids → Fatty acids

    • Polysaccharides → Monosaccharides

  • Building blocks utilized in anabolic reactions.

Aerobic Cellular Respiration

  • Up to 38 ATP molecules produced from each glucose molecule:

    • 2 ATP from Glycolysis

    • 2 ATP from Krebs Cycle

    • ~34 ATP from Electron Transport Chain.

Digestive Enzymes

  • Three main types of enzymes:

    • Carbohydrases: Break down carbohydrates.

    • Proteases: Break down proteins.

    • Lipases: Break down lipids.

  • Always include the suffix “-ase”.

Carbohydrates

  1. Monosaccharides (e.g., Glucose, Fructose, Galactose): Primary fuel for ATP production.

  2. Disaccharides (e.g., Sucrose, Lactose, Maltose)

  3. Polysaccharides (e.g., Starch, Glycogen, Cellulose)

Autotrophs vs Heterotrophs

  • Autotrophs: Make their own organic materials including carbohydrates, lipids, proteins, and nucleic acids.

  • Heterotrophs: Obtain energy by consuming organic materials.

Chemical Cycling: Photosynthesis vs Cellular Respiration

  • Photosynthesis inputs:

    • Carbon Dioxide from air

    • Water from soil

  • Outputs:

    • Glucose

    • Oxygen

Glycolysis

  • Breakdown of glucose into pyruvic acid.

  • Takes place in the cytoplasm.

  • Anaerobic process: Does not require oxygen.

Fermentation in Human Muscle Cells

  • After around 15 seconds of anaerobic action, muscle cells switch to fermentation for ATP:

    • Relies on glycolysis which yields 2 ATP.

    • Produces Lactic Acid, causing muscle soreness.

Photosynthesizing Organisms

  • Include Plants, Algae, Cyanobacteria.

  • These organisms are referred to as photoautotrophs.

Basic Photosynthetic Structures

  • Chloroplasts: Locations of photosynthesis, contain chlorophyll (pigment crucial for solar energy conversion).

The Calvin Cycle

  • Light-independent reactions organized into three stages:

    1. Fixation

    2. Reduction

    3. Regeneration

Eukaryotic Chromosomes

  • Chromatin: Made of DNA and protein.

  • Organizes and controls gene activity.

Interphase and its Divisions

  • Interphase: Cells grow, double contents, prepare for division (90% of cell cycle).

    • Divided into G1, S (DNA synthesis), G2 phases.

  • In S phase, chromosomes are duplicated, creating sister chromatids.

Mitosis

  • Cell division part of the cell cycle.

  • Involves redistribution of duplicated chromosomes to daughter nuclei.

Tumors

  • Benign Tumors: Non-cancerous, localized; can disrupt function but generally removable.

  • Malignant Tumors: Cancerous, spread to other tissues and create new tumors.

Diploid and Haploid Cells

  • Diploid: Cells with pairs of chromosomes (2n), somatic cells.

  • Haploid: Single set of chromosomes (n), gametes produced through meiosis.

Mitosis vs. Meiosis

  • Mitosis: Growth, repair, produces identical diploid cells.

  • Meiosis: Forms haploid gametes, responsible for sexual reproduction.

Alleles

  • Different versions of a gene that affect inherited traits.

  • Homozygous (identical alleles) vs. Heterozygous (different alleles).

Dominant and Recessive Alleles

  • Dominant Alleles: Determine appearance.

  • Recessive Alleles: No effect unless in homozygous state.

  • Law of segregation explains separation of alleles during gamete formation.

Genotype vs Phenotype

  • Genotype: Genetic makeup (e.g., PP, Pp).

  • Phenotype: Observable traits (e.g., purple or white flowers).

Testcross Example

  • To determine an unknown genotype (e.g., a black Lab): can be BB or Bb.

Dominant Traits vs Wild Type

  • Wild Type: Most common traits in nature.

  • Dominance does not imply more frequency; recessive traits can be more common.

Recessive Disorders

  • Most genetic disorders are recessive.

  • Carriers appear normal but can have offspring with disorders.

Structure of DNA

  • DNA: Made of nucleic acids (Phosphate group, Ribose sugar, Nitrogenous bases).

  • Bases in DNA: Adenine (A), Thymine (T), Cytosine (C), Guanine (G).

DNA Replication

  • Involves many enzymes, especially DNA polymerases that form bonds between nucleotides.