Review: Each molecule of glucose yields up to 38 molecules of ATP

Transcription

1 Review: Each molecule of glucose yields up to 38 molecules of ATP Electron shuttle across membrane Mitochondrion Cytoplasm 2 NADH 2 NADH (or 2 FADH 2 ) 2 NADH 6 NADH 2 FADH 2 GLYCOLYSIS Glucose 2 Pyruvate 2 Acetyl CoA CITRIC ACID CYCLE OXIDATIVE PHOSPHORYLATION (Electron Transport and Chemiosmosis) + 2 ATP + 2 ATP + about 34 ATP by substrate-level phosphorylation by substrate-level phosphorylation by oxidative phosphorylation Maximum per glucose: About 38 ATP Photosynthesis: Uses light energy, CO 2 and water to make glucose and oxygen Sun Inflow of light energy O 2 CO 2 CO 2 Air Loss of heat energy Chemical energy Producers Cycling of Chemical nutrients Consumers H 2 O Decomposers Ecosystem Soil

2 Photosynthesis: Uses light energy, CO 2 and water to make glucose and oxygen Light energy 6 CO H 2 O C 6 H 12 O O 2 Carbon dioxide Water PHOTOSYNTHESIS Glucose Oxygen gas Photosynthesis: Uses light energy, CO 2 and water to make glucose and oxygen Why is this important? Global warming A renewable energy source

3 Plants, algae, and certain bacteria are the major producers of the biosphere They produce their own food and sustain themselves without eating other organisms They are called photoautotrophs Producers of food consumed by virtually all organisms Figure 7.1A D Photosynthesis occurs in chloroplasts In plants, photosynthesis occurs primarily in the leaves

4 Photosynthesis occurs in chloroplasts In plants, photosynthesis occurs primarily in the leaves Leaves contain specialized cells that facilitate and carry out photosynthesis Photosynthesis occurs in chloroplasts In plants, photosynthesis occurs primarily in the leaves Leaves contain specialized cells that facilitate and carry out photosynthesis The mesophyll cells contain chloroplasts

5 Photosynthesis occurs in chloroplasts In plants, photosynthesis occurs primarily in the leaves Leaves contain specialized cells that facilitate and carry out photosynthesis The mesophyll cells contain chloroplasts chloroplasts, which contain stroma, and stacks of thylakoids called grana Photosynthesis: Uses light energy, CO 2 and water to make glucose and oxygen Light energy 6 CO H 2 O C 6 H 12 O O 2 Carbon dioxide Water PHOTOSYNTHESIS Glucose Oxygen gas

6 Photosynthesis is a process similar to cellular respiration In cellular respiration; glucose is oxidized and O 2 is reduced glucose Photosynthesis is a process similar to cellular respiration In cellular respiration; glucose is oxidized and O 2 is reduced NADH High-energy electrons carried by NADH NADH FADH 2 and Glucose GLYCOLYSIS Pyruvate CITRIC ACID CYCLE OXIDATIVE PHOSPHORYLATION (Electron Transport and Chemiosmosis) Cytoplasm Mitochondrion ATP CO 2 CO 2 ATP ATP Substrate-level phosphorylation Substrate-level phosphorylation Oxidative phosphorylation

7 Photosynthesis is a process similar to cellular respiration In cellular respiration; glucose is oxidized and O 2 is reduced In photosynthesis; H 2 O is oxidized and CO 2 is reduced glucose Photosynthesis is a process similar to cellular respiration In cellular respiration; glucose is oxidized and O 2 is reduced In photosynthesis; H 2 O is oxidized and CO 2 is reduced glucose glucose

8 Photosynthesis: The light reactions and the Calvin cycle Photosynthesis: The light reactions and the Calvin cycle The light reactions convert light energy to chemical energy and produce O 2

9 Photosynthesis: The light reactions and the Calvin cycle The light reactions convert light energy to chemical energy and produce O 2 The Calvin cycle assembles sugar molecules from CO 2 using ATP and NADPH from the light reactions The light reactions: Certain wavelengths of visible light, absorbed by pigments, drive the light reactions of photosynthesis

10 The light reactions: Certain wavelengths of visible light, absorbed by pigments, drive the light reactions of photosynthesis The light reactions: Certain wavelengths of visible light, absorbed by pigments, drive the light reactions of photosynthesis The light is captured by a PHOTOSYSTEM ATP e e e e e e NADPH Mill makes ATP Photon e Figure 7.8B Photon Photosystem II Photosystem I

11 PHOTOSYSTEM: Each photosystem consists of Light-harvesting complexes of pigments Excited state Light energy Heat light Chlorophyll molecule Ground state PHOTOSYSTEM Each photosystem consists of Light-harvesting complexes of pigments A reaction center with a primary electron acceptor that receives excited electrons from a reaction-center chlorophyll

12 PHOTOSYSTEM Each photosystem consists of Light-harvesting complexes of pigments A reaction center with a primary electron acceptor that receives excited electrons from a reaction-center chlorophyll The excited electrons are passed from the primary electron acceptor to electron transport chains Stroma Photon 1 Photosystem II Photon Photosystem I NADP + + H + NADPH 6 Thylakoid membrane 2 e P680 4 e 5 P700 Thylakoid space Figure 7.8A 3 H 2 O 1 2 O H + Electron transport chain Provides energy for synthesis of by chemiosmosis ATP Chemiosmosis powers ATP synthesis in the light reactions The electron transport chain pumps H + into the thylakoid space Chloroplast Stroma (low H + concentration) Lig\ht Light H + H H + ADP + + P ATP NADP + + H + NADPH H + Thylakoid membrane H 2 O H + H O H+ H+ H + H + Photosystem II Electron Photosystem I transport chain Thylakoid space (high H + concentration) H + H + H + H + H + ATP synthase

13 Chemiosmosis powers ATP synthesis in the light reactions The electron transport chain pumps H + into the thylakoid space The diffusion of H + back across the membrane through ATP synthase powers the phosphorylation of ADP to produce ATP Chloroplast Stroma (low H + concentration) Lig\ht Light H + H H + ADP + + P ATP NADP + + H + NADPH H + Thylakoid membrane H 2 O H + H O H+ H+ H + H + Photosystem II Electron Photosystem I transport chain Thylakoid space (high H + concentration) H + H + H + H + H + ATP synthase Chemiosmosis powers ATP synthesis in the light reactions The electron transport chain pumps H + into the thylakoid space The diffusion of H + back across the membrane through ATP synthase powers the phosphorylation of ADP to produce ATP ATP and NADPH power sugar synthesis in the Calvin cycle Chloroplast Stroma (low H + concentration) Lig\ht Light H + H H + ADP + + P ATP NADP + + H + NADPH H + Thylakoid membrane H 2 O H + H O H+ H+ H + H + Photosystem II Electron Photosystem I transport chain Thylakoid space (high H + concentration) H + H + H + H + H + ATP synthase

14 The Calvin cycle: Occurs in the chloroplast s stroma Consists of carbon fixation, reduction, release of G3P, and regeneration of RuBP Light H 2 O CO 2 Chloroplast Thylakoid membranes Photosystem II Electron transport chains Photosystem I O 2 LIGHT REACTIONS NADP + ADP P + ATP NADPH RUBP CALVIN CYCLE 3-PGA (in stroma) G3P Sugars CALVIN CYCLE Stroma Cellular respiration Cellulose Starch Other organic compounds Some plants have special adaptations that save water In C 3 plants a drop in CO 2 and rise in O 2 when stomata close on hot dry days and have to waste energy with photorespiration

15 Some plants have special adaptations that save water In C 3 plants a drop in CO 2 and rise in O 2 when stomata close on hot dry days and have to waste energy with photorespiration C 4 plants first fix CO 2 into a four-carbon compound that provides CO 2 to the Calvin cycle Mesophyll cell CO 2 4-C compound CO 2 CALVIN CYCLE Figure 7.12 (left half) Sugarcane Bundle-sheath cell 3-C sugar C 4 plant Some plants have special adaptations that save water In C 3 plants a drop in CO 2 and rise in O 2 when stomata close on hot dry days and have to waste energy with photorespiration C 4 plants first fix CO 2 into a four-carbon compound that provides CO 2 to the Calvin cycle CAM plants open their stomata at night Making a four-carbon compound used as a CO 2 source during the day CO 2 Night 4-C compound CO 2 CALVIN CYCLE 3-C sugar Day Pineapple Figure 7.12 (right half) CAM plant

16 Photosynthesis moderates global warming removes CO 2 from the atmosphere Sunlight Some heat energy escapes into space ATMOSPHERE Radiant heat trapped by CO 2 and other gases The Cellular Basis of Reproduction and Inheritance

17 Sexual reproduction Fertilization of egg by sperm produces offspring Creates a variety of offspring Sexual reproduction Fertilization of egg by sperm produces offspring Creates a variety of offspring Asexual reproduction Offspring are produced by a single parent, without the participation of sperm and egg And their offspring are genetic copies of the parent and of each other LM 340!

18 Sexual reproduction Fertilization of egg by sperm produces offspring Creates a variety of offspring Asexual reproduction Offspring are produced by a single parent, without the participation of sperm and egg And their offspring are genetic copies of the parent and of each other Cells arise only from preexisting cells Cell division is at the heart of the reproduction Cell division: Prokaryotes Reproduce asexually by cell division Prokaryotic chromosome 1 Plasma membrane Cell wall Duplication of chromosome and separation of copies 2 Continued elongation of the cell and movement of copies 3 Division into two daughter cells Figure 8.3B

19 Cell division: Prokaryotes Reproduce asexually by cell division As the cell replicates its single chromosome, the copies move apart and the growing membrane then divides the cells Prokaryotic chromosome 1 2 Plasma membrane Cell wall Duplication of chromosome and separation of copies Continued elongation of the cell and movement of copies 3 Division into two daughter cells Figure 8.3B Cell division: Prokaryotes Reproduce asexually by cell division As the cell replicates its single chromosome, the copies move apart and the growing membrane then divides the cells Prokaryotic chromosome 1 2 Plasma membrane Cell wall Duplication of chromosome and separation of copies Continued elongation of the cell and movement of copies 3 Division into two daughter cells Figure 8.3B

20 Cell division: Prokaryotes Reproduce asexually by cell division As the cell replicates its single chromosome, the copies move apart and the growing membrane then divides the cells Prokaryotic chromosome 1 2 Plasma membrane Cell wall Duplication of chromosome and separation of copies Continued elongation of the cell and movement of copies 3 Division into two daughter cells Figure 8.3B Cell division: Prokaryotes Reproduce asexually by cell division As the cell replicates its SINGLE chromosome, the copies move apart and the growing membrane then divides the cells Eukaryotes Reproduce both asexually by cell division and sexually After a eukaryotic cell replicates its MULTIPLE chromosomes, the copies move apart and the growing membrane then divides the cells

21 Eukaryotic cell division: involves the copying (replication) of each chromatids followed by the careful separation of sister chromatids results in two daughter cells, each containing a complete and identical set of chromosomes Centromere Chromosome duplication Sister chromatids Chromosome distribution to daughter cells Figure 8.4C CONTROL

22 Interphase: Chromosomes duplicate and cell parts are made CONTROL Mitotic phase: Duplicated chromosomes are evenly distributed CONTROL

23 CONTROL The stages of cell division: Mitosis LM 250! INTERPHASE PROPHASE PROMETAPHASE Centrosomes (with centriole pairs) Chromatin Early mitotic Centrosome spindle Fragments of nuclear envelope Kinetochore Nuclear envelope Plasma membrane Chromosome, consisting ot two sister chromatids Centromere Spindle microtubules

24 The stages of cell division: Mitosis METAPHASE ANAPHASE TELOPHASE AND CYTOKINESIS Metaphase plate Cleavage furrow Spindle Figure 8.6 (Part 2) Daughter chromosomes Nuclear envelope forming The stages of cell division: Meiosis Two rounds of connected mitosis without DNA replication in between.

25 The stages of cell division: Mitosis METAPHASE ANAPHASE TELOPHASE AND CYTOKINESIS Metaphase plate Cleavage furrow Spindle Figure 8.6 (Part 2) Daughter chromosomes Nuclear envelope forming Cytokinesis differs for plant and animal cells In animals cytokinesis occurs by a constriction of the cell (cleavage) Cleavage furrow SEM 140! Cleavage furrow Contracting ring of microfilaments Figure 8.7A Daughter cells

26 Cytokinesis differs for plant and animal cells In animals cytokinesis occurs by a constriction of the cell (cleavage) In plants a membranous cell plate splits the cell in two TEM 7,500! Cell wall New cell wall Vesicles containing cell wall material Cell plate Daughter cells Figure 8.7B Control of the cell cycle and cell division Anchorage, cell density, and chemical growth factors affect cell division Most animal cells divide only when stimulated, and some not at all Cells anchor to dish surface and divide. When cells have formed a complete single layer, they stop dividing (densitydependent inhibition). If some cells are scraped away, the remaining cells divide to fill the dish with a single layer and then stop (density-dependent inhibition).

27 Control of the cell cycle and cell division Anchorage, cell density, and chemical growth factors affect cell division Most animal cells divide only when stimulated, and some not at all After forming a single layer, cells have stopped dividing. Growth factors are proteins secreted by cells that stimulate other cells to divide Providing an additional supply of growth factors stimulates further cell division. The cell cycle control system A set of proteins within the cell that control the cell cycle Control

28 The cell cycle control system A set of proteins within the cell that control the cell cycle Control Growth factors are proteins that bind to specific receptors (other proteins) on the plasma membrane and control the cell cycle Growth factor Plasma membrane Receptor protein Signal transduction pathway Relay proteins G 1 checkpoint G 1 Control system S M G 2 Figure 8.9B

29 What cell happens if cell in our body grow out of control? What cell happens if cell in our body grow out of control?

30 What cell happens if cell in our body grow out of control? Medical care provided by mercy ships What cell happens if cell in our body grow out of control?

31 Review of the functions of mitosis: Growth, cell replacement, and asexual reproduction When the cell cycle operates normally, mitotic cell division functions in: Growth Replacement of damaged or lost cells Asexual reproduction Figure 8.11A LM 500!