cellular respiration cellular respiration extracts energy from the chemical bonds of molecules 2...
TRANSCRIPT
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