PLANT BIOLOGY

Dermal tissue Ground tissue Vascular tissue Figure 35.8 Figure 35.8 The three tissue systems. Dermal tissue Ground tissue Vascular tissue

Cortex Vascular cylinder Epidermis Key to labels Zone of Fig. 35-13 Cortex Vascular cylinder Epidermis Key to labels Zone of differentiation Root hair Dermal Ground Vascular Zone of elongation Apical meristem Zone of cell division Root cap 100 µm

Root with xylem and phloem in the center (typical of eudicots) Fig. 35-14a1 Epidermis Key to labels Cortex Dermal Endodermis Ground Vascular Vascular cylinder Pericycle Xylem 100 µm Phloem (a) Root with xylem and phloem in the center (typical of eudicots)

Root with xylem and phloem in the center (typical of eudicots) Fig. 35-14a2 (a) Root with xylem and phloem in the center (typical of eudicots) Endodermis Key to labels Pericycle Dermal Ground Vascular Xylem Phloem 50 µm

100 m Emerging lateral root Cortex Vascular cylinder Pericycle 1 Figure 35.15a 100 m Emerging lateral root Cortex Vascular cylinder Figure 35.15 The formation of a lateral root. Pericycle 1

100 m Epidermis Lateral root 2 Figure 35.15b Figure 35.15 The formation of a lateral root. 2

100 m Epidermis Lateral root 3 Figure 35.15c Figure 35.15 The formation of a lateral root. 3

Water molecule Root hair Soil particle Water Water uptake from soil Figure 36.13a Water molecule Root hair Soil particle Figure 36.13 Ascent of xylem sap. Water Water uptake from soil

CYTOPLASM EXTRACELLULAR FLUID Hydrogen ion Proton pump  + H+  + ATP Figure 36.7a CYTOPLASM EXTRACELLULAR FLUID  + H+  + Hydrogen ion ATP  + H+ H+ H+ H+ H+ H+  + Proton pump Figure 36.7 Solute transport across plant cell plasma membranes. H+  + (a) H+ and membrane potential

H+/sucrose cotransporter Sucrose (neutral solute) Figure 36.7b  + H+ S H+  + H+ H+  + H+ H+ H+ S S H+ H+ H+ S S S  + H+  + H+/sucrose cotransporter Figure 36.7 Solute transport across plant cell plasma membranes. Sucrose (neutral solute)  + (b) H+ and cotransport of neutral solutes

Nitrate H+NO3 cotransporter  + H+ H+ NO3  + NO3  H+ + H+ H+ H+ Figure 36.7c  + H+ H+ NO3  + NO3  + H+ H+ H+ H+ Nitrate H+ H+ NO3 NO3  NO3 + NO3  + H+ H+NO3 cotransporter Figure 36.7 Solute transport across plant cell plasma membranes. H+  H+ + (c) H+ and cotransport of ions

 + K+ Potassium ion  + K+  K+ + K+ K+ K+ K+  + Ion channel  + Figure 36.7d  + K+ Potassium ion  + K+  K+ + K+ K+ K+ K+  + Ion channel Figure 36.7 Solute transport across plant cell plasma membranes.  + (d) Ion channels

Pathway along apoplast Figure 36.10b Casparian strip Endodermal cell Pathway along apoplast Pathway through symplast Figure 36.10 Transport of water and minerals from root hairs to the xylem.

Vascular cylinder (stele) Figure 36.10a Plasma membrane Casparian strip Apoplastic route Vessels (xylem) Figure 36.10 Transport of water and minerals from root hairs to the xylem. Symplastic route Root hair Epidermis Endodermis Vascular cylinder (stele) Cortex

This year’s growth (one year old) Leaf scar Figure 35.12 Apical bud Bud scale Axillary buds This year’s growth (one year old) Leaf scar Node Bud scar One-year-old side branch formed from axillary bud near shoot tip Internode Last year’s growth (two year old) Leaf scar Stem Figure 35.12 Three years’ growth in a winter twig. Bud scar Growth of two years ago (three years old) Leaf scar

Developing vascular strand Figure 35.16 Shoot apical meristem Leaf primordia Young leaf Developing vascular strand Figure 35.16 The shoot tip. Axillary bud meristems 0.25 mm

Sclerenchyma (fiber cells) Ground tissue Figure 35.17 Phloem Xylem Sclerenchyma (fiber cells) Ground tissue Ground tissue connecting pith to cortex Pith Epidermis Key to labels Epidermis Cortex Vascular bundles Vascular bundle Figure 35.17 Organization of primary tissues in young stems. Dermal 1 mm 1 mm Ground (a) Cross section of stem with vascular bundles forming a ring (typical of eudicots) (b) Vascular Cross section of stem with scattered vascular bundles (typical of monocots)

Growth ring Vascular ray Heartwood Secondary xylem Sapwood Figure 35.22 Growth ring Vascular ray Heartwood Secondary xylem Sapwood Vascular cambium Figure 35.22 Anatomy of a tree trunk. Secondary phloem Bark Layers of periderm

Adhesion – strong attraction of water molecules to walls of xylem Movement of Water Up Xylem Vessels                                                                              Adhesion – strong attraction of water molecules to walls of xylem Cohesion – strong attraction of water molecules to each other

(a) Cutaway drawing of leaf tissues Figure 35.18a Key to labels Sclerenchyma fibers Dermal Cuticle Stoma Ground Vascular Upper epidermis Palisade mesophyll Spongy mesophyll Bundle- sheath cell Figure 35.18 Leaf anatomy. Lower epidermis Xylem Vein Cuticle Phloem Guard cells (a) Cutaway drawing of leaf tissues

The Process of Transpiration                                                                                                 

Guard cells turgid/ Stoma open Guard cells flaccid/ Stoma closed Figure 36.15a Guard cells turgid/ Stoma open Guard cells flaccid/ Stoma closed Radially oriented cellulose microfibrils Cell wall Vacuole Figure 36.15 Mechanisms of stomatal opening and closing. Guard cell (a) Changes in guard cell shape and stomatal opening and closing (surface view)

Activation of cellular responses Figure 39.3 CELL WALL CYTOPLASM 1 Reception 2 Transduction 3 Response Relay proteins and Activation of cellular responses second messengers Receptor Figure 39.3 Review of a general model for signal transduction pathways. Hormone or environmental stimulus Plasma membrane

De-etiolation (greening) response proteins Figure 39.4-3 1 Reception 2 Transduction 3 Response Transcription factor 1 CYTOPLASM NUCLEUS Plasma membrane cGMP Protein kinase 1 P Second messenger Transcription factor 2 Phytochrome P Cell wall Protein kinase 2 Transcription Light Translation Figure 39.4 An example of signal transduction in plants: the role of phytochrome in the de-etiolation (greening) response. Ca2 channel De-etiolation (greening) response proteins Ca2

Scutellum (cotyledon) Figure 39.11 Aleurone 1 2 3 Endosperm -amylase Sugar GA GA Water Figure 39.11 Mobilization of nutrients by gibberellins during the germination of grain seeds such as barley. Radicle Scutellum (cotyledon)

Methane (reducing agent) Oxygen (oxidizing agent) Figure 9.3 Reactants Products becomes oxidized Energy becomes reduced Figure 9.3 Methane combustion as an energy-yielding redox reaction. Methane (reducing agent) Oxygen (oxidizing agent) Carbon dioxide Water

Gamma rays Micro- waves Radio waves Figure 10.7 1 m 105 nm 103 nm 1 nm 103 nm 106 nm (109 nm) 103 m Gamma rays Micro- waves Radio waves X-rays UV Infrared Visible light Figure 10.7 The electromagnetic spectrum. 380 450 500 550 600 650 700 750 nm Shorter wavelength Longer wavelength Higher energy Lower energy 48

Hydrocarbon tail (H atoms not shown) Figure 10.11 CH3 in chlorophyll a CH3 CHO in chlorophyll b Porphyrin ring Figure 10.11 Structure of chlorophyll molecules in chloroplasts of plants. Hydrocarbon tail (H atoms not shown) 50

Chloroplast Outer membrane Thylakoid Intermembrane space Stroma Granum Figure 10.4b Chloroplast Outer membrane Thylakoid Intermembrane space Stroma Granum Thylakoid space Inner membrane Figure 10.4 Zooming in on the location of photosynthesis in a plant. 1 m 51

Calvin Cycle Light Reactions [CH2O] (sugar) Figure 10.6-4 H2O CO2 Light NADP ADP + P i Calvin Cycle Light Reactions ATP Figure 10.6 An overview of photosynthesis: cooperation of the light reactions and the Calvin cycle. NADPH Chloroplast [CH2O] (sugar) O2 52

Figure 10.14-1 Primary acceptor e P680 Light 2 e P680 1 Light Figure 10.14 How linear electron flow during the light reactions generates ATP and NADPH. Pigment molecules Photosystem II (PS II) 55

Figure 10.14-2 Primary acceptor e H2O 2 H + 1/2 O2 e e P680 Light 3 1/2 O2 e e P680 1 Light Figure 10.14 How linear electron flow during the light reactions generates ATP and NADPH. Pigment molecules Photosystem II (PS II) 56

Electron transport chain Figure 10.14-3 Primary acceptor 4 Electron transport chain Pq 2 e H2O 2 H Cytochrome complex + 3 1/2 O2 Pc e e 5 P680 1 Light ATP Figure 10.14 How linear electron flow during the light reactions generates ATP and NADPH. Pigment molecules Photosystem II (PS II) 57

Electron transport chain Figure 10.14-4 Primary acceptor Primary acceptor 4 Electron transport chain Pq e 2 e H2O 2 H Cytochrome complex + 3 1/2 O2 Pc e e P700 5 P680 Light 1 Light 6 ATP Figure 10.14 How linear electron flow during the light reactions generates ATP and NADPH. Pigment molecules Photosystem I (PS I) Photosystem II (PS II) 58

Electron transport chain Figure 10.14-5 Electron transport chain Primary acceptor Primary acceptor 4 7 Electron transport chain Fd Pq e 2 e 8 e e H2O NADP 2 H Cytochrome complex NADP reductase + H + 3 1/2 O2 NADPH Pc e e P700 5 P680 Light 1 Light 6 ATP Figure 10.14 How linear electron flow during the light reactions generates ATP and NADPH. Pigment molecules Photosystem I (PS I) Photosystem II (PS II) 59

Mill makes ATP NADPH ATP Photosystem II Photosystem I e e e e e Figure 10.15 e e e Mill makes ATP NADPH e e e Photon Figure 10.15 A mechanical analogy for linear electron flow during the light reactions. e ATP Photon Photosystem II Photosystem I 60

STROMA (low H concentration) Cytochrome complex NADP reductase Figure 10.18 STROMA (low H concentration) Cytochrome complex NADP reductase Photosystem II Photosystem I Light 3 Light 4 H+ NADP + H Fd Pq NADPH 2 Pc H2O 1 1/2 O2 THYLAKOID SPACE (high H concentration) +2 H+ 4 H+ To Calvin Cycle Figure 10.18 The light reactions and chemiosmosis: the organization of the thylakoid membrane. Thylakoid membrane ATP synthase ADP + P i ATP STROMA (low H concentration) H+ 61

Figure 10.19 The Calvin cycle. Input 3 (Entering one at a time) CO2 Phase 1: Carbon fixation Rubisco 3 P P Short-lived intermediate 3 P P 6 P Ribulose bisphosphate (RuBP) 3-Phosphoglycerate Figure 10.19 The Calvin cycle. 62

Figure 10.19 The Calvin cycle. Input 3 (Entering one at a time) CO2 Phase 1: Carbon fixation Rubisco 3 P P Short-lived intermediate 3 P P 6 P Ribulose bisphosphate (RuBP) 3-Phosphoglycerate 6 ATP 6 ADP Calvin Cycle 6 P P 1,3-Bisphosphoglycerate 6 NADPH 6 NADP 6 P i Figure 10.19 The Calvin cycle. 6 P Glyceraldehyde 3-phosphate (G3P) Phase 2: Reduction 1 P G3P (a sugar) Glucose and other organic compounds Output 63

Figure 10.19 The Calvin cycle. Input 3 (Entering one at a time) CO2 Phase 1: Carbon fixation Rubisco 3 P P Short-lived intermediate 3 P P 6 P Ribulose bisphosphate (RuBP) 3-Phosphoglycerate 6 ATP 6 ADP 3 ADP Calvin Cycle 6 P P 3 ATP 1,3-Bisphosphoglycerate 6 NADPH Phase 3: Regeneration of the CO2 acceptor (RuBP) 6 NADP 6 P i 5 P Figure 10.19 The Calvin cycle. G3P 6 P Glyceraldehyde 3-phosphate (G3P) Phase 2: Reduction 1 P G3P (a sugar) Glucose and other organic compounds Output 64

Photosynthetic cells of C4 plant leaf Bundle- sheath cell Figure 10.20a C4 leaf anatomy Mesophyll cell Photosynthetic cells of C4 plant leaf Bundle- sheath cell Vein (vascular tissue) Figure 10.20 C4 leaf anatomy and the C4 pathway. Stoma 65

The C4 pathway Mesophyll cell CO2 PEP carboxylase Oxaloacetate (4C) Figure 10.20b The C4 pathway Mesophyll cell CO2 PEP carboxylase Oxaloacetate (4C) PEP (3C) ADP Malate (4C) ATP Pyruvate (3C) Bundle- sheath cell CO2 Calvin Cycle Figure 10.20 C4 leaf anatomy and the C4 pathway. Sugar Vascular tissue 66

Calvin Cycle Calvin Cycle Figure 10.21 Sugarcane Pineapple C4 CAM CO2 CO2 1 CO2 incorporated (carbon fixation) Mesophyll cell Organic acid Organic acid Night Figure 10.21 C4 and CAM photosynthesis compared. CO2 CO2 Bundle- sheath cell 2 CO2 released to the Calvin cycle Day Calvin Cycle Calvin Cycle Sugar Sugar (a) Spatial separation of steps (b) Temporal separation of steps 67

Electrons carried via NADH Substrate-level phosphorylation Figure 9.6-1 Electrons carried via NADH Glycolysis Glucose Pyruvate CYTOSOL MITOCHONDRION Figure 9.6 An overview of cellular respiration. ATP Substrate-level phosphorylation

Electrons carried via NADH Electrons carried via NADH and FADH2 Figure 9.6-2 Electrons carried via NADH Electrons carried via NADH and FADH2 Pyruvate oxidation Glycolysis Citric acid cycle Glucose Pyruvate Acetyl CoA CYTOSOL MITOCHONDRION Figure 9.6 An overview of cellular respiration. ATP ATP Substrate-level phosphorylation Substrate-level phosphorylation

Electrons carried via NADH Electrons carried via NADH and FADH2 Figure 9.6-3 Electrons carried via NADH Electrons carried via NADH and FADH2 Oxidative phosphorylation: electron transport and chemiosmosis Pyruvate oxidation Glycolysis Citric acid cycle Glucose Pyruvate Acetyl CoA CYTOSOL MITOCHONDRION Figure 9.6 An overview of cellular respiration. ATP ATP ATP Substrate-level phosphorylation Substrate-level phosphorylation Oxidative phosphorylation

Protein complex of electron carriers Figure 9.15 H H H Protein complex of electron carriers H Cyt c IV Q III I ATP synth- ase II 2 H + 1/2O2 H2O FADH2 FAD NADH Figure 9.15 Chemiosmosis couples the electron transport chain to ATP synthesis. NAD ADP  P i ATP (carrying electrons from food) H 1 Electron transport chain 2 Chemiosmosis Oxidative phosphorylation

Oxidative phosphorylation: electron transport and chemiosmosis Figure 9.16 Electron shuttles span membrane MITOCHONDRION 2 NADH or 2 FADH2 2 NADH 2 NADH 6 NADH 2 FADH2 Oxidative phosphorylation: electron transport and chemiosmosis Glycolysis Pyruvate oxidation Citric acid cycle Glucose 2 Pyruvate 2 Acetyl CoA  2 ATP  2 ATP  about 26 or 28 ATP Figure 9.16 ATP yield per molecule of glucose at each stage of cellular respiration. About 30 or 32 ATP Maximum per glucose: CYTOSOL

Ethanol, lactate, or other products Figure 9.18 Glucose Glycolysis CYTOSOL Pyruvate No O2 present: Fermentation O2 present: Aerobic cellular respiration MITOCHONDRION Ethanol, lactate, or other products Acetyl CoA Figure 9.18 Pyruvate as a key juncture in catabolism. Citric acid cycle