Botany 110 Purdue Final Exam

What is a molecule?

One or more elements held together by bonds

Levels of organization

Molecules, cells, tissues, organs, organ systems, individual, population, community, ecosystem

Covalent bond

A chemical bond that involves sharing a pair of electrons

Ions

Atoms that lost or gained an electron

Ionic bond

When one or more electrons are transferred from one atom to another

Cation

Loses an electron, therefore, positively charged

Anion

Gains an electron, therefore, negatively charged

4 Macromolecules of life

carbohydrates, lipids, proteins, nucleic acids

3 types of membrane transportation

1. Simple diffusion

2. Facilitated diffusion

3. Active diffusion

Hydrogen bonding

Weakest bond but used in DNA to hold together nucleotides

Start codon

AUG (methionine); the codon that begins all RNA.

Stop codon

UAG, UAA, or UGA; the codon that ends all RNA.

Function of stems

1. Support

2. Transport

3. Produce food

4. Produce more stems

Nodes

The point where leaves or branches attatch

Buds

New stems or flowers form in the axil of leaves

Internodes

Length of stem between nodes

Modifications of the stem

Bulbs, corms, tubers

Function of leaves

1. Photosynthesis

2. Storage

3. Transpiration

Monocot

Single cotyledon; netted vein pattern

Dicot

Two cotyledons; parallel vein pattern

Compound leaf

Multiple leaves attached at a stem and then to the main stem

Simple leaf

Attatched directly to the stem

Alternate leaf arrangement

Opposite leaf arrangement

Whorl leaf arrangement

Function of roots

1. water and mineral uptake

2. anchorage

3. storage

4. produce lateral roots

Functions of the flower

1. reproduction

2. production of seeds

What is the pistil comprised of?

stigma, style, and ovary

What is the stamen comprised of?

anther and filament

Monoecious

has male and female reproductive parts

Dioecious

distinct male and female plants

Norman Borlaug

Father of the Green Revolution; created high yield wheat

Why is plant breeding important?

photo and thermos insensitivity, moisture and salt tolerance, elimination of toxic substances

Genetic markers

a DNA sequence associated with a given trait in one or more plant populations

Main tissue types

1. dermal

2. ground

3. vascular

What is dermal tissue (epidermis) in plants?

forms the outer layer of a root, shoot, or leaf that covers and protects the plant

What is ground tissue in plants?

Tissue between the dermal tissue and vascular tissue of a non-woody plant.

What are the functions of ground tissue?

Photosynthesis, storage, and support.

What are the three types of ground tissue?

Parenchyma, sclerenchyma, and collenchyma.

Types of dermal tissues

trichomes, guard cells, pavements cells

What is the vascular tissue in plants?

xylem and phloem

Cuticle

A waxy covering on the surface of stems and leaves that slows down evaporation

What are guard cells controlled by?

Changes in turgor pressure

Function of guard cells

open and close stomata and control transpiration

Parenchyma

comprise the bulk of the plant: the cortex of stems, roots, and leaves- photosynthesis occurs here- starch storage

Sclerenchyma

Thick walled cells, lignified, provide structure

Collenchyma

Wall thickening (cellulose), gritty texture

Xylem function

Transports water and dissolved minerals from the root up to all the other parts of the plant

-Xylem tubes are made up from dead cells

What is the primary function of phloem?

Transports food nutrients such as glucose from the leaves to other parts of the plant.

In which directions does phloem transport nutrients?

Moves in both directions.

What are the main components of phloem?

Composed of sieve elements.

What are the two paths for water and minerals to enter the vascular system?

Symplastic route and the apoplastic route

Symplastic route

through the cytosol

Apoplastic route

through the cell walls and extracellular spaces

Source cells

cells in plant tissue where sugars are made

Sink cells

cells in plant tissue where sugars are to be used or stored

Function of the vascular cambium

adds layers of vascular tissue called secondary xylem (wood) and secondary phloem

Function of the lateral meristem

expands vascular and epidermal tissue

Tap root

Fibrous root

Where does cellular respiration take place?

mitochondria and cytoplasm

Cellular respiration equation

C6H12O6+6O2---> 6CO2+6H2O+36ATP+heat

Where does glycolysis occur?

The cytoplasm

What occurs during glycolysis

glucose is converted to pyruvate

What is the second step of respiration?

The production of acetyl CoA

The production of acetyl-CoA

pyruvate moves into the mitochondria is converted into one molecule of CO2 and one molecule of 2-carbon acetyl which attaches to coenzyme A in order to make acetyl CoA

What is the third step of respiration?

The Krebs Cycle

The Krebs Cycle

pyruvic acid is broken down into carbon dioxide in a series of energy-extracting reactions

Electron transport chain

A sequence of electron carrier molecules (membrane proteins) that shuttle electrons during the redox reactions that release energy used to make ATP.

Chemiosmosis

A process for synthesizing ATP using the energy of an electrochemical gradient and the ATP synthase enzyme

Fermentation

an anaerobic process that allows glycolysis to continue

Where does photosynthesis occur?

chloroplasts (plant cells)

Photosynthesis equation

6CO2 + 6H2O ------> C6H12O6 + 6O2

Light-dependent reactions

reactions of photosynthesis that use energy from light to produce ATP and NADPH

does photosystem 1 or photosystem 2 happen first?

Photosystem 2 occurs first

Light-independent reactions

set of reactions in photosynthesis that do not require light; energy from ATP and NADPH is used to build high-energy compounds such as sugar; also called the Calvin cycle

Visible light wavelength

Short wave length- higher energy

Where do light independent reactions take place?

stroma of the chloroplast

Where do light dependent reactions take place?

thylakoid membrane

C3 Photosynthesis

The most common form of photosynthesis

C4 Photosynthesis

process that first converts CO2 into a 4-carbon molecule in the mesophyll cells, converts that product to malate and then shuttles it to the bundle sheath cells, where the malate releases CO2 and rubisco picks it up as if all were normal

CAM photosynthesis

Desert plants store CO2 at night as malic acid in the vacuole to use during the day. Allows them to keep leaves closed during day and reduce water loss.

3 Parts of a nucleotide

1. Phosphate group

2. 5 carbon sugar

3. Nitrogenous base

Pyrimidines

single ring bases- cytosine and thymine

Purines

double ring bases- adenine and guanine

Chargraff's rule

# of adenines = # thymines; # of guanines = # of cytosines

Complimentary base pairing principle

A+T= 2 hydrogen bonds

C+G= 3 hydrogen bonds

Double helix structure

2 polynucleotide strands wrapped around each other

Leading strand

the new complementary DNA strand synthesized continuously along the template strand toward the replication fork in the mandatory 5' to 3' direction

Lagging strand

The strand in replication that is copied 3' to 5' as Okazaki fragments and then joined up.

RNA primer

short segment of RNA used to initiate synthesis of a new strand of DNA during replication

DNA polymerase

Enzyme involved in DNA replication that joins nucleotides to produce a DNA molecule on the 3' end

DNA helicase

unwinds DNA

DNA ligase

seals areas between bases

DNA primase and topoisomerase

begins DNA replication

What does "prime" mean?

the position of the carbons in the sugar ring

What is attached to the 3' carbon?

hydroxyl group (-OH)

What is attached to the 5' carbon?

phosphate group (PO4-)

What way can the daughter DNA strand only grow?

5'->3'

What base does uracil replace in RNA?

Thymine