Plants and Humans Exam 2

Photosynthesis

How Plants use sunlight to produce their food

Use sunlight energy to change it into the energy stored in the bonds of glucose

Cellular Respiration

Take the energy stored in the bonds of glucose and BREAK IT DOWN to produce cellular energy

Photosynthesis Reactants

6CO2 + 6H2O + sunlight

Photosynthesis Products

C6H12O6 + 6O2

Where does photosynthesis occur?

Chloroplasts of Leaf Cells

Pigment

Substances that give off a color due to light absorbance and reflection.

Chlorophyll

Main pigment for photosynthesis; Mainly absorbs in the red and blue areas of the light spectrum

Chlorophyll B

Associated pigment for photosynthesis; absorbs in the red-orange and blue areas of the light spectrum

Carotenoids

Absorbs in the blue-green and violet areas of the light spectrum

Chloroplasts are

Double Membraned

Granum

stack of thylakoids

Thylakoid

Quarter-Shaped Disc

Stroma

Fluid inside the chloroplast

Stages of Photosynthesis

1) Light-Dependent Stage

2) Calvin Cycle/Light-Independent Stage

Light-Dependent Stage

Light Energy Splits water, resulting in oxygen

ATP is formed

Occurs in the thylakoids

Calvin Cycle/Light-Independent Stage

Carbon Dioxide enters the leaf

Produces sugars

Occurs in the stroma

ATP is

adenosine triphosphate, the cell's energy currency

Reactants of Cellular Respiration

C6H12O6 + 6O2

Products of Cellular Respiration

6CO2 + 6H2O + ATP

Where does MOST of cellular respiration occurs?

Mitochondria

Mitochondria has

Double Membranes

Cristae

Folds on the inner mitochondrial membrane

Mitochondrial Matrix

Innermost compartment of a mitochondrion (fluid)

aerobic respiration

requires oxygen

anaerobic respiration

Does not use oxygen

Steps of Cellular Respiration

1) Glycolysis

*Transition Step-

2) Citric Acid Cycle/Krebs Cycle

3) Electron Transport Chain

Glycolysis

Sugar Splitting

Glucose splits into 2 pyruvate molecules

Happens in the cytosol

Transition Step*

2 Pyruvate molecules are changed into 2 acetyl coenzyme A molecules

Citric Acid Cycle/Krebs Cycle

Occurs in the mitochondrial Matrix

Glucose is oxidized to carbon dioxide

Requires Oxygen

Electron Transport Chain (MOST IMPORTANT STEP)

Occurs on the inner mitochondrial membrane

Requires oxygen

Produces most of the ATP

1) Perception

A) External Environment

B) Internal Plant Body

2) Information Transfer

Hormones

3) Response

Action that is taken

Stimulus/Stimuli

Something that happens that causes an activity

Examples of Stimuli

Drought

Bugs

Not enough sunlight

Weather

Touch

More nutritious soil

Statocytes

Gravity-sensing cells in the root

Statoliths

Starch grains within statocytes

Hormones

Chemical Messengers

-Made in small amounts, but have big effects

5 Basic Plants Hormones

Auxin

Cytokinin

Abscisic Acid

Gibberellin

Ethylene

1) Auxin (most important)

Apical Dominance, Cell elongation, cell suppression

2) Cytokinin

Activation cell division, dormant buds, "antagonist to Auxin"

3) Abscisic Acid

Involved in stress responses

4) Gibberellin

Involved in seed germination

5) Ethylene

Fruit Ripening

Seed Germination

A) The embryo takes in water and swells

B) The embryo secretes gibberellin into the aleurone layer, and enzymes produced

C) The enzymes move into the endosperm

D) The enzymes digest the endosperm to provide nutrients for the embryo

Tropic Response

Permanent, growth associated with a stimulus (toward-positive, away-negative, at an angle)

Nastic Response

Temporary, non-growth associated with a stimulus

Morphogenic Response

Change in the development or quality of a plant

All-or-None Response

A response is only present after a threshold is met

Ex. Venus Fly Trap

Dosage-Dependent Response

Response depends on the dose

Etiolation

Differences in development when seedlings are grown in the dark

-Less complex-looking

-Not green/tan-beige-yellow

-Leaves are not developed

Phototropism

Plants bending toward the light

-First studied in oat tips

Gravitropism

Roots bending down towards gravity

Apical Dominance

Terminal bud produces auxin that suppresses the growth of axillary buds

Climacteric Fruits

Ethylene involved in ripening

- Tomatoes, bananas, apples

Non-Climacteric Fruits

Ethylene NOT involved in ripening

- Cherries, Grapes, Oranges

Fruit Ripening Process

-Color Changes

-Texture Changes

-Size Changes

-Smell Changes

-Taste Changes

2 Basic Types of Reproduction

Sexual and Asexual

Advantages of Both Sexual and Asexual reproduction

Genetically Different (Sexual) and 1 Parent Involved (Asexual)

Disadvantages of Both Sexual and Asexual reproduction

2 Parents involved (Sexual) and No Genetic Diversity (Asexual)

Vegetative Propagation

Plant sends out a runner along the ground that can form a new plant

Asexual reproduction

Cell Cycle

Life cycle of the cells from one division to the next

Interphase

Cell growth, copies DNA

Cell Division/Nuclear Division

Division (divide) the DNA

Cytokinesis

Divide the cytoplasm

Uses a cell plate

Interphase Process

Longest Part of the Cell Cycle

G1, Synthesis, and G2

G1 (Gap 1)

Cell Grows, make proteins

S (Synthesis)

DNA is copied

G2 (Gap 2)

Cell growth, final preparations for cell/nuclear division

Cell/Nuclear Division Process

2 options: mitosis and meiosis

Mitosis

Occurs in body cells

Associated with asexual reproduction

4 phases; PMAT

Cytokinesis Process

Division of the cytoplasm

Chromatin

DNA and protein

Chromosome

Condensed chromatin (easily visible)

Sister Chromatids

Duplicated Chromosome

Diploid

2 Complete sets of chromosomes

Haploid

1 Complete set of chromosomes

Prophase (Mitosis)

1) Chromatin condenses so x-shaped sister chromatids are easily seen

2) Nuclear envelope begins to break down

3) Nucleolus Degrades

4) The spindle begins to form

Metaphase (Mitosis)

Sister chromatids attached to the spindle and line up in the MIDDLE of the cell

Anaphase (Mitosis)

Sister Chromatids are separated and are now called chromosomes

Telophase (Mitosis)

1) Chromosomes unravel into chromatin

2) Nuclear envelope reappear

3) Nucleoli reappear

4) The spindle breaks down

Meiosis

Occurs in reproductive cells

Reduce the number of chromosomes by half

Associated with sexual reproduction

Meiosis I and Meiosis II

Meiosis I

separates homologous chromosomes

Meiosis II

Separate x-shaped structures

Prophase I (Meiosis I)

Homologous chromosomes pair up

Crossing-Over occurs

Metaphase I (Meiosis I)

Homologous chromosomes line up in the middle of the cell

Anaphase I (Meiosis I)

Homologous chromosomes separate

Telephase I (Meiosis I)

The amount of DNA is halved

Cytokinesis I (Meiosis I0

Division of the cytoplasm

2 Daughter cells are formed

Prophase II (Meiosis II)

Spindle starts forming

Nuclear envelopes break down

Nucleoli degrade

DNA condenses in the form of x-shaped structures

Metaphase II (Meiosis II)

DNA lines up in the middle of the cell

Anaphase II (Meiosis II)

DNA is separated (no longer x-shaped)

Telephase II (Meiosis II)

Spindle breaks down

DNA unravels into chromatin

Nucleoli reappear

Nuclear envelopes reappear

Cytokinesis II (Meiosis II)

Division of the cytoplasm

4 cells with half the amount of DNA from the starting point (genetically different)

Mitosis Characteristics

Asexual Reproduction

Same amount of DNA

1x through Interphase

1x through PMAT

2 cells produced

Genetically identical

Body/Somatic Cells

Meiosis Characteristics

Sexual Reproductions

Half the amount of DNA

1x through interphase

2x through PMAT

4 cells produced

Genetically different

Reproductive Cells

Alternation of Generations

Flip between the sporophyte generation and the gametophyte generation

Sporophyte

Diploid (produces spores)

Gametophyte

Haploid (produces gametes)

Gametophyte (Haploid) Makes

Gametes (sex cells) (haploid)