BIO-2

### Vaccination

- Injecting inactive or dead pathogens

- Triggers immune response

- Produces memory cells → immunity without illness

### Antibiotics

- Kill or stop growth of bacteria

- Don’t work on viruses

- Overuse can lead to resistance

### Photosynthesis

Carbon dioxide + water → glucose + oxygen

(in the presence of light and chlorophyll)

### Aerobic Respiration

- Happens in mitochondria

- Equation:

Glucose + oxygen → carbon dioxide + water + energy (ATP)

-Requires Oxygen

### Anaerobic Respiration

- Without oxygen

- Less energy produced

- In animals:

Glucose → lactic acid + energy

- In yeast (fermentation):

Glucose → ethanol + carbon dioxide + energy

### Ecology

- Community: all living organisms in an area

- Ecosystem: community + non-living environment

### What are enzymes?

- Biological catalysts

- Speed up chemical reactions in cells

- Made of proteins

### How enzymes work

- Substrate: the molecule the enzyme acts on

- Active site: the part of enzyme where substrate fits

- Lock and key model: substrate fits active site exactly

### Types of Enzymes

Amylase*: breaks starch → glucose (found in saliva, pancreas)

- Protease: breaks proteins → amino acids (stomach, pancreas)

- Lipase: breaks fats → fatty acids + glycerol (pancreas, small intestine)

###How to test for Starch

  • Add iodine solution to the sample (yellow-brown color).

  • If starch is present, iodine turns blue-black.

  • Add amylase enzyme to the sample and let it react.

  • After reaction, add iodine again.

  • If starch is broken down, iodine stays yellow-brown.

    ###Biuret Test)

  • Procedure:

    1. Add a few drops of Copper(II) sulfate solution to the sample.

    2. Then, add sodium hydroxide (NaOH) to the mixture.

    3. Observation:

      • If protein is present, the solution will change from blue to purple

  • The Copper(II) sulfate reacts with the peptide bonds in proteins, forming a purple complex when protein is present.

### Evolution

- Allopatric Speciation: new species form due to geographic isolation (e.g., one population isolated by a mountain).

- Sympatric Speciation: new species form without geographic isolation, usually due to behavioral or ecological differences.

### Genetic Drift

- Random changes in allele frequencies in a small population due to chance events (not natural selection).

### Convergent & Divergent Evolution

- Convergent Evolution: different species evolve similar traits due to similar environmental pressures (e.g., wings in birds and bats).

- Divergent Evolution: species with a common ancestor evolve different traits due to different environments (e.g., Darwin's finches).

### Artificial Selection

- Humans select for specific traits in organisms (e.g., breeding dogs for certain characteristics, crops with high yield).