Bio Final

Carbohydrates

Primary energy source; stored as glycogen (animals) or starch (plants)

Monomer of Carbohydrates

Monosaccharides (e.g., glucose)

Examples of Carbohydrates

Sugars, starches, cellulose

Lipids

Energy storage, cell membrane structure (phospholipids), insulation

Structure of Lipids

Glycerol + fatty acids

Examples of Lipids

Triglycerides, phospholipids, steroids

Nucleic Acids

Genetic information storage & protein synthesis

Monomer of Nucleic Acids

Nucleotide (phosphate, sugar, nitrogenous base)

DNA

Double-stranded, deoxyribose sugar, thymine (T)

RNA

Single-stranded, ribose sugar, uracil (U)

Proteins

Structure, enzymes, signaling, transport

Monomer of Proteins

Amino acids

Enzymes

Speed up reactions; affected by temperature, pH, and substrate concentration

Examples of Proteins

Hemoglobin, insulin, enzymes (e.g., amylase)

Nucleus

Contains DNA, controls cell activities

Mitochondria

ATP production (cellular respiration)

Chloroplast

Photosynthesis (plants & algae)

Ribosomes

Protein synthesis

Rough ER

Protein synthesis

Smooth ER

Lipid synthesis

Golgi Apparatus

Modifies, sorts, and packages proteins

Lysosomes

Digest cellular waste (animal cells)

Cell Membrane

Regulates what enters/exits the cell (phospholipid bilayer)

Passive Transport

No energy required

Diffusion

Movement from high to low concentration

Osmosis

Water movement across a membrane

Facilitated Diffusion

Uses transport proteins

Active Transport

Moves substances against concentration gradient (low to high)

Example of Active Transport

Sodium-potassium pump

Hypotonic

Water enters cell (cell swells)

Hypertonic

Water exits cell (cell shrinks)

Isotonic

No net water movement

Cellular Respiration

C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP (energy)

Photosynthesis

6CO2 + 6H2O + Light → C6H12O6 + 6O2

Exergonic

Releases energy (e.g., cellular respiration)

Endergonic

Requires energy (e.g., photosynthesis)

Prokaryotic Binary Fission

Asexual reproduction; DNA replicates, cell splits

Eukaryotic Cell Cycle Stages

Interphase (G1, S, G2), Mitosis (PMAT), Cytokinesis

Cancer

Uncontrolled cell division due to mutations

DNA Replication Enzymes

Helicase: Unzips DNA, DNA Polymerase: Adds nucleotides, Ligase: Seals gaps

Transcription

DNA → mRNA

Translation

mRNA → Protein

Example of DNA to Protein

DNA: TAC GGA TTT, mRNA: AUG CCU AAA, Amino Acids: Methionine-Proline-Lysine

Meiosis I

Homologous chromosomes separate

Meiosis II

Sister chromatids separate

Results of Meiosis

4 unique haploid gametes

Oogenesis

1 egg + 3 polar bodies (unequal division)

Spermatogenesis

4 equal sperm cells

Karyotype

Chromosome chart; detects abnormalities

Nondisjunction

Chromosomes fail to separate (e.g., Trisomy 21 = Down syndrome)

Central Dogma

Describes the flow of genetic information from DNA to RNA to protein.

Replication

DNA makes a copy of itself.

Transcription

DNA is transcribed into mRNA.

Translation

mRNA is translated into a protein.

DNA

Stores genetic information.

RNA

Acts as a messenger between DNA and ribosomes.

Ribosomes

Site of protein synthesis.

RNA Polymerase

Enzyme involved in transcription.

Mitosis

Type of cell division that results in two genetically identical daughter cells.

Prophase

Chromosomes condense, nuclear membrane dissolves, spindle fibers form.

Metaphase

Chromosomes align at the cell's equator.

Anaphase

Sister chromatids separate and move to opposite poles.

Telophase

Nuclear membrane reforms, chromosomes decondense.

Cytokinesis

Cytoplasm divides, forming two identical cells.

Meiosis

Two-stage cell division process that reduces chromosome number by half, creating four genetically unique haploid gametes.

Prophase I

Chromosomes pair up (synapsis), crossing over occurs.

Metaphase I

Homologous chromosomes align in the middle.

Anaphase I

Homologous pairs separate.

Telophase I & Cytokinesis

Two haploid cells form.

Prophase II

New spindle fibers form.

Metaphase II

Chromosomes align in the middle.

Anaphase II

Sister chromatids separate.

Telophase II & Cytokinesis

Four haploid cells form.

Genetic Variation

Introduced through crossing over and independent assortment.

Somatic Cells

Cells that undergo mitosis.

Gametes

Cells that undergo meiosis (sperm and eggs).

Mitosis

A type of cell division that results in two identical daughter cells.

Meiosis

A type of cell division that results in four unique daughter cells.

Number of divisions in Mitosis

1

Number of divisions in Meiosis

2

Number of daughter cells in Mitosis

2

Number of daughter cells in Meiosis

4

Genetic composition in Mitosis

Identical

Genetic composition in Meiosis

Unique

Chromosome number in Mitosis

Diploid (2n)

Chromosome number in Meiosis

Haploid (n)

Occurs in Mitosis

Somatic cells

Occurs in Meiosis

Gametes

Central Dogma of Molecular Biology

The process by which DNA is transcribed to RNA and then translated into proteins.

Transcription

The process of copying a segment of DNA into RNA.

Translation

The process of synthesizing proteins from mRNA.

Crossing over in meiosis

A process that increases genetic diversity by exchanging genetic material between homologous chromosomes.

Spindle fibers

Structures that help separate chromosomes during cell division.

DNA

A nucleic acid that stores genetic instructions for protein synthesis.

RNA

A nucleic acid that transfers genetic information and is involved in protein synthesis.

Sugar in DNA

Deoxyribose

Sugar in RNA

Ribose

Strands in DNA

Double-stranded

Strands in RNA

Single-stranded

Bases in DNA

A, T, C, G