2. Cells Review AIR Test Biology

3. Cell Theory 1.All living things are made up of cells. 2.Cells are the smallest working units of all living things. 3.All cells come from preexisting cells through cell division.

4. Prokaryotic Do not have internal structures surrounded by membranes Few internal structures (DNA, ribosomes, cytoplasm) One-celled organisms (Bacteria)

5. Eukaryotic Contain organelles (internal structures) surrounded by membranes Multicellular organisms Plant Animal

6. Animal Cell vs. Plant Cell

7. The Parts Cell membrane: controls movement of materials in and out of the cell. Cell Wall: provides structural support and protects cell (plant/bacterial cells). All cells contain cytoplasm (fluid inside the cell) Organelles: –Nucleus: control center of cell (contains DNA) –Mitochondria: burn food to produce energy –Ribosomes: make proteins –Lysosomes: store digestive enzymes –Endoplasmic reticulum: transport materials within cell –Vacuoles: where digestion occurs (store excess fluids) –Chloroplasts: where glucose is produced (plants) Some cells have: –Flagella: movement- whiplike structure (movement) –Cilia: movement- hairlike structure (movement)

8. Chromosome Structure Review Except for the gametes, humans have 46 chromosomes (23 pairs) in the nucleus of every cell. Except for the gametes, humans have 46 chromosomes (23 pairs) in the nucleus of every cell. Chromosomes are long strands of DNA (genetic code). Chromosomes are long strands of DNA (genetic code). When chromosomes are uncoiled, they are called chromatin. When chromosomes are uncoiled, they are called chromatin. When chromosomes are coiled, they look like an “x”. When chromosomes are coiled, they look like an “x”.

9. Chromosome Structure Review Centromere- holds 2 chromatids together Chromatids- Each half of a chromosome Each chromatid is a double helix (twisted ladder)

10. Cells with different numbers of chromosomes Diploid (somatic cell) – A cell consisting of homologous chromosomes. In humans, this cell has 46 chromosomes. One chromosome of a pair came from the mother and one from the father. All cells in the human body are diploid except sex cells. Diploid (somatic cell) – A cell consisting of homologous chromosomes. In humans, this cell has 46 chromosomes. One chromosome of a pair came from the mother and one from the father. All cells in the human body are diploid except sex cells. Haploid (gamete) – A cell that does not contain chromosome pairs. The sperm and egg are haploid and, in humans, have 23 chromosomes. Haploid (gamete) – A cell that does not contain chromosome pairs. The sperm and egg are haploid and, in humans, have 23 chromosomes.sperm eggsperm egg

11. Chromosome Shorthand n = # of unique chromosomes (haploid) n = # of unique chromosomes (haploid) 2n = # of chromosomes in pairs (diploid) 2n = # of chromosomes in pairs (diploid) XX xx XX xx Homologous Pair n=4 Haploid cell 2n=8 Diploid cell X X x x

12. Differences between mitosis and meiosis Mitosis Mitosis –Metaphase- chromosomes are in single file –2 product cells (diploid) –Somatic cells (non- sex) produced –4 phases (PMAT) Meiosis Meiosis –Metaphase I chromosomes are aligned as pairs –4 product cells (haploid) –Sex cells (gametes) produced –Synapsis and crossing over occurs during Prophase I –8 phases (PMAT 1 and 2)

13. How do cells obtain organic compounds for energy? Heterotrophs: Cannot make their own food Autotrophs: Can make their own food – Photoautotrophs: Use energy from the sun (photosynthesis) to produce organic compounds (glucose) Plants, algae and some bacteria – Chemoautotrophs: Use energy stored in inorganic compounds (chemosynthesis) to produce organic compounds Some bacteria found at the hydrothermal vents of the seafloor

14. Photosynthesis Method of converting light energy from the sun into chemical energy that cells can use – Divided into the light-dependent and light-independent reactions 6CO 2 + 6 H 2 O + light energy → C 6 H 12 O 6 + 6O 2

15. Getting energy out of food Plants and animals both use glucose from photosynthesis for cell fuel. Glucose (or other carbs), proteins, and fats are not a form of energy that our cells can use. Cellular respiration converts glucose into a usable energy form (ATP) for cells.

16. Cellular Respiration Overview The reactions of cellular respiration occur the same way in plants and animals. Overall Reaction: C 6 H 12 O 6 + 6O 2 → 6CO 2 + 6H 2 O

17. Aerobic Cellular Respiration Oxygen required=aerobic Aerobic respiration follows glycolysis. It occurs in the mitochondria. There are 2 main parts to aerobic respiration: Kreb’s Cycle Electron Transport Chain

18. Anaerobic Cellular Respiration Some organisms (some bacteria) thrive in environments with little or no oxygen No oxygen used= anaerobic Anaerobic organisms experience anaerobic cellular respiration after glycolysis.

19. AP Biology Overview  The cell membrane separates a living cell from its nonliving surroundings  Controls traffic in & out of the cell  selectively permeable  allows some substances to cross more easily than others- “choosy”  Made of phospholipids, proteins, cholesterol, and carbohydrates.

20. AP Biology Getting through cell membrane  Passive Transport  diffusion with the concentration gradient  high  low  Simple diffusion  diffusion of hydrophobic and small molecules  Lipids (fats)  Facilitated diffusion  diffusion of hydrophilic and large molecules  through a protein channel  high  low concentration gradient  Active transport  diffusion against the concentration gradient  low  high  uses a protein pump  requires ATP ATP

21. AP Biology Transport summary simple diffusion facilitated diffusion active transport ATP