Cellular Respiration Cellular Respiration extracts energy from the chemical bonds of molecules 2 Inputs 3 outputs.

Cellular Respiration

Cellular Respiration extracts energy from the

chemical bonds of molecules

2 Inputs

3 outputs

Cellular respiration has 3 stages:

1. Glycolysis2. Krebs Cycle (Citric

Acid Cycle)3. Electron Transport

Chain (ETC)

Modified from http://courtneystanifer.edublogs.org/

6 O2 + C6H12O6 → 6 CO2 + 6 H2O + ATP + HEAT

6 H2O + 6 CO2 → 6 O2 + C6H12O6

© 2011 Pearson Education, Inc.

8.1 Photosynthesis and Energy

Photosynthesis: Where the pieces come from

3 inputs 2 products

Photosynthesis uses energy from sunlight

to make food.

Movie Time

Amoeba Sisters – Photosynthesishttps://youtu.be/uixA8ZXx0KU

Photosynthesis

A 2 step process where plants convert light energy to chemical energy and

store it in the form of sugar.

Occurs in the Chloroplast – an organelle in plant cells that captures light for photosynthesis

http://photo-dictionary.com/phrase/2090/leaf-structure.html

Three Types of Photosynthesis

Figure 8.1

petiole

blade

epidermis

mesophyll cells

epidermis

stomatanucleus

chloroplast

cell wall

vacuole

thylakoids

stroma

granum

inner membrane

outer membrane

thylakoid

thylakoid membrane

thylakoid compartment

Energy from sunlightis absorbed bypigments in thethylakoid membrane.

1. Leaf

2. Stomata- opening that allow CO2to

pass in and water vapor to pass out.

3. Single cells within a leaf contain chloroplasts—the actual sites of photosynthesis.

4. Each chloroplast has a liquid material, called the stroma, filled with thylakoids. These thylakoids sometimes stack on one another to create a granum.

5. Granum

Figure 8.4

There are two primary stages in photosynthesis

Step 1: Light Reaction

Step 2: Dark Reaction

Chloroplasts:

Photons cause electrons in chlorophyll to enter an excited state.

• In light reactions, e- from water are energetically boosted by sunlight

• These e- are passed along through a series of electron carriers, ending up as part of NADPH, which carries them to the Calvin Cycle

Kinetic energy Made up of little energy packets called photons Different photons carry different amounts of

energy, carried as waves Plant pigments absorb specific wavelengths

Photosynthesis is powered by light energy

Electromagnetic Spectrum

Range of energy that is organized into waves of different lengths.

Shorter the wavelength, higher the energy.

Energy going into the plant

Energy going into the plant

Energy bounces off the plant

Two actions of great consequence take place in the light reactions.

1. Water is split, yielding both electrons & oxygen.– The electrons move through the light reactions.– The oxygen is what organisms breathe in.

2. The electrons from water get an energy boost from the sun, and then get transferred to

an electron acceptor.

The Light Reactions

Figure 8.7

ATP

Fig 4-17

Dark Reaction: The Calvin Cycle

Occurs in stroma

Series of chemical reactions

Enzymes are recycled

1. Carbon fixation. An enzyme called rubisco brings together three molecules of CO2 with three molecules of the sugar RuBP. In this reaction, one carbon from each CO2 molecule is being added to the five-carbon RuBP, and this is being done three times. The three resulting six-carbon molecules are immediately split into six three-carbon molecules named 3-PGA (3-phosphoglyceric acid).

2. Energizing the sugar. In two separate reactions, six ATP molecules react with six 3-PGA, in each case transferring a phosphate onto the 3-PGA. The six 3-PGA derivatives oxidize (gain electrons from) six NADPH molecules; in so doing, they are transformed into the energy-rich sugar G3P (glyceraldehyde 3-phosphate).

3. Exit of product. One molecule of G3P exits as the output of the Calvin cycle. This molecule, the product of photosynthesis, can be used for energy or transformed into materials that make up the plant.

4. Regeneration of RuBP. In several reactions, five molecules of G3P are transformed into three molecules of RuBP, which enter the cycle.

3 ATP Calvin cycle

sugar

3 moleculesof RuBP

3 ADP

3 ATP

from lightreactions

5 moleculesof G3P

1 molecule of G3P

glucose and other derivatives

6 moleculesof G3P

3. Exit of product

4. Regeneration of RuBP

3 molecules

Rubisco

1. Carbon fixation

2. Energizing the sugar

6

3 molecules

6 molecules of3-PGA

from lightreactions

6 ATP

6 ADP

6 molecules of3-PGAderivative

fromlightreactions

ATP6

6

Figure 8.8

The Calvin Cycle

• In this second stage, the Calvin cycle, the electrons are brought together with CO2 and a sugar.

• The product is a high-energy sugar in a process powered by ATP that is produced in the light reactions.

Your Turn

• Complete the worksheet.• You may work in groups, but each person will

turn in their own paper.

Photosynthesis and Energy

• Photosynthesis has made possible life as we know it on Earth because the organic material produced in photosynthesis (a sugar) is the source of food for most of Earth’s living things.

• Photosynthesis also is responsible for the atmospheric oxygen used by many living things in cellular respiration.

Figure 8.2

Energy comes from the sun andthen, in photosynthesis, is stored in plants in thecomplex molecules wecall carbohydrates

The process of cellular respiration converts the energy stored in carbohydrates to ATP, the most important energy-transfer molecule in living things.

Powers manychemical reactions

Sunlight

ATP

Recap 2 parts of photosynthesis:

“photo” - light energy is transformed into chemical energy while splitting water molecules & producing oxygen.

“synthesis” - Calvin cycle, & it occurs in the stroma of the chloroplast.

NADPH

NADP+

H2OSunlight

© 2011 Pearson Education, Inc.

24.1 The Roles and Characteristics of Plants

Roles of Plants

• Photosynthesis indirectly feeds many life-forms

• The oxygen plants produce as a by-product is vital to many organisms

• Plant products are important to human beings

Characteristics of Plants

• With a few exceptions, all plants – Are multicellular – Fixed in one spot – Carry out photosynthesis

• Cell wall • Most have chloroplasts

Life Cycle of Plants• Plants reproduce

through an alternation of generations: the sporophyte and the gametophyte

• Within a given species, these two generations can differ greatly in size and structure.

Plant alternation of generations

multicellulargametophytespores

meiosis

gametes

fertilization

zygotemulticellularsporophyte

haploid (1n)

diploid (2n)

2n

1n

© 2011 Pearson Education, Inc.

24.2 Types of Plants

Types of Plants

• The four principal categories of plants are:– Bryophytes (mosses)– seedless vascular plants (ferns)– Gymnosperms (coniferous trees)– Angiosperms (a wide array of plants)

mosses ferns conifersflowering

plants

flowers

seeds

vascular tissue

multicellularity

green algae(ancestors)

(a) Moss (b) Ferns (c) Conifers (d) Flowering plants

Types of Plants

Figure 24.6

Bryophytes• Close living relatives of the earliest plants that

made the transition from water to land• No vascular system - tend to be low lying• Inhabit damp environments & their sperm get

to eggs primarily by swimming through water

Figure 24.7

Seedless Vascular Plants

• Have a vascular system but do not produce seeds in reproduction

• Their sperm must move through water to fertilize eggs

Figure 24.8

Gymnosperms

• Seed-bearing plants with seeds that are not encased in tissue called fruit (naked seeds)

• Only ~1000 species, but in northern latitudes, where trees, such as pine and spruce, they dominate landscapes

wing

seed

protectiveseed coat

embryo

nutritionaltissue

Figure 24.10

• Gymnosperms produce seeds in carrying out reproduction.

• Seeds are reproductive structures that include a plant embryo, its food supply, & a tough, protective casing.

male cone

pollen

1. Wind carries pollen to female cone.

female cone

seedling

maturetree

5. New pine tree begins to grow.

4. Seed germinates.

2. Sperm within the pollen fertilizes one egg within the cone.

3. Embryo begins to develop within seed.

seed

Figure 24.11

Angiosperms• Flowering plants, produce seeds encased in fruit• Most dominant group of plants ~260K species• Not only plants with flowers, but almost all trees except

for conifers, all important food crops, cactus, shrubs, & common grass.

© 2011 Pearson Education, Inc.

24.3 Angiosperm–Animal Interactions

Angiosperm–Animal Interactions

• Pollen grains generally are transferred from one plant to another by animals– insects and birds

• To induce pollination, angiosperm flowers– produce nectar – look good– smell good

Figure 24.13

Endosperm

• Once pollination occurs, there is an embryo that needs to develop

• Angiosperm seeds contain tissue called endosperm, which functions as food for the growing embryo

• Endosperm supplies much of the food that human beings eat. – Rice and wheat grains consist largely of

endosperm

wheat

endosperm

seed coat (bran)

embryo (wheat germ)

Endosperm

Figure 24.15

Fruit• Angiosperm seeds are wrapped in a tissue

called fruit• Fruit spreads seeds b/c animals will eat &

excrete

Figure 24.16

© 2011 Pearson Education, Inc.

24.4 Responding to External Signals

Gravitropism

• Plants are able to sense their orientation with respect to the Earth and direct the growth of their roots and shoots accordingly– roots into the Earth, shoots toward the sky

http://o.quizlet.com/i/1YYCO3Tn9Ke1kxcUa26YYA_m.jpg

Phototropism• Plants will bend toward a source of light to

gain additional access through the process of phototropism, meaning a curvature of shoots in response to light.

http://ykonline.yksd.com/distanceedcourses/Courses/Biology/lessons/FourthQuarter/Chapter13/13-1/images/phototropism1.gif

Thigmotropism• The growth of a plant in response to touch• Some plants can climb upward on other

objects by making contact with them & encircling them in growth to gain additional access to light.

http://krivsky-thigmotropism.yolasite.com/resources/images.jpg?timestamp=1353820582088

© 2011 Pearson Education, Inc.

25.1 The Structure of Angiosperms

Categorizing Flowering Plants

• Shoots include the plant’s– Leaves - photosynthesis

– Stems – structure & nutrient storage

– Flowers – reproductive structures

• Roots– Absorb water & nutrients– Anchor the plant– Act as nutrient storage sites

stamen

anther

filament

petals

sepals

bud flower

pedicel

receptacle

ovary

style

stigma

carpelParts of the Flower

Figure 25.10

Sexy Plant Time• Most flowers have both male & female parts• Carpel - female

– Stigma: pollen grains are deposited– Style: raises the stigma high enough to catch pollen– Ovary: fertilization & early embryo development

• Stamen - male– Consists of a slender filament topped by an anther,

the chambers of which contain the cells that will develop into sperm-containing pollen grains

© 2011 Pearson Education, Inc.

25.2 Monocots and Dicots:Not all angiosperms are the same

Classification

• Angiosperms are classified according to how many cotyledons (embryonic leaves) they have:– Narrow-leafed Monocots: 1 cotyledon– Broad-leafed Dicots: 2 cotyledons

• Differ in structure in many ways

Figure 25.11

Monocots vs. Dicots

Monocots

embryonicleaves

matureleaves

roots

vascularbundles

type ofgrowth

flowerparts

examples

onecotyledon

narrow leaves

parallelveins

fibrous rootsystem

scattered throughoutstem

only primarygrowth

multiples ofthree

orchids, wheat, rice, bananas

Dicots

twocotyledons

broadleaves

branchingveins

taprootsystem

arrangedin ring instem

may havesecondarywoodygrowth

multiplesof four orfive

oak and maple trees, cacti,sunflowers

75%

© 2011 Pearson Education, Inc.

25.3 Plant Tissue Types

dermal tissue - plant’s outer coveringvascular tissue - plumbing ground tissue

Meristematic tissue – growth

Four Types of Tissue

Figure 25.13

Dermal Tissue

sunlightin

gasesexchanged

invaders out

cuticleepidermis

guard cellsof stomata

trichome

guard cells: epidermal cells modified for regulation of gas exchange

trichomes: hairlike outgrowthsof epidermal cells

(a) (b)

Figure 25.14

Vascular Tissue

xylem

tracheid

vessel element

sieveelement

companion cell

phloem

vascular bundle

Figure 25.15

© 2011 Pearson Education, Inc.

25.4 Primary Growth in Angiosperms

Meristematic Tissue

immature leaf

shoot apicalmeristem

meristematictissue (lateralbud)

root apicalmeristem

root cap

Figure 25.17

• Plants grow only at the tips of their roots and shoots.

• Plant growth can go on for the life of most plants.

© 2011 Pearson Education, Inc.

25.5 Fluid Movement: The Vascular System

Xylem – moves the water

Figure 25.19

tracheid

xylem

vessel element

Water Transport by Transpiration

1. Water evaporates from stomata on underside of leaves.

2. Water from stem is pulled up through xylem to replace water lost from leaves.

3. Water is pulled out of soil into roots to replace water lost from stem.

plant’s energynot required

H2O

H2OH2O

Figure 25.20

phloem

sieve element

companion cell

Phloem – where the sugar flows

Figure 25.21

Sugar Transport by Pressure Flow

source

1. Photosynthesis in leaves produces sugar, which is loaded into the phloem.

2. Sugars are transported through phloem to fruits, stems, and roots.

3. Sugars are stored in tissues such as roots.

sink

plant’s energyrequired

Figure 25.22

© 2011 Pearson Education, Inc.

25.6 Sexual Reproduction in Angiosperms

Movie Time

Crash Course Biology #38https://youtu.be/ExaQ8shhkw8?t=5m35s

maturesporophyte

seedgerminationand growth

sporophytegeneration

seed

embryo

zygote

fertilization

embryo sac(contains egg)

megaspore

ovary

gametophytegeneration

stigma

spermmovementto egg

stigma

microspores

sperm cellstube cell

pollen grainsanther

1.

2.

3.

4.

5.

Figure 25.24

pollen grain

stigma

style

ovary

ovule

egg

pollination

embryo sac

pollen tubegrowth

doublefertilization

fusion of onesperm cell withnuclei of centralcell to formendosperm

fusion of onesperm cell withegg to formzygote

tube cellnucleus

spermcells

pollentube

tube cell

spermcells

Sexual Reproduction

Figure 25.25