plant form & function study guide #1

when did the earliest life occur?

3.5 billion years ago

heterotrophic v. autotropic

heterotrophic: can’t live on their own; depend on outside sources (fungi, animals, organic matter)

autotrophic: self-feeders, can make their own organic molecules

what are the important events for adaptation of photosynthetic organisms moving from sea to seashore?

specialized structure (root-like) for anchoring, new forms developed, multiple-celled organisms, strong cell walls for support

what is the most critical environmental factor when plants moved from the sea to the land?

the access to water becomes limited, and water loss protection occurs

epidermal cells: covered with waxy cuticle (prevent water loss)

guard cells: controls opening/closing of stomata to control gas and water exchange

what are the functions for the aerial parts and the roots of a plant?

aerial parts: photosynthesis, support, transport of materials

roots parts: anchor, collect water and minerals

what kind of organic molecule is the most abundant organic molecule in nature?

carbohydrates

what is the basic unit for cellulose?

beta glucose

what are the chemical features of monosaccharides

single unit that functions as the building blocks of high order of saccharaides

• sources of energy

• hydrophilic

• soluble in water

what is the transport form of sugar in a plant?

sucrose

what are the characteristics of fatty acids?

building blocks of lipids

• insoluable in water

what is the basic structure of a amino acid?

amino group attached to a hydrogen, R group, and a carboxyl group

• building blocks of proteins

how many amino acids were used to build up proteins?

20

what are the products if a peptide undergoes hydrolysis?

amino acids

what are the features of the primary, secondary, tertiary and quaternary structures of a protein?

primary: amino acid sequence

secondary: alpha helix linked by hydrogen bonds and a beta sheet; adjacent portions line up

tertiary: polypeptide chains

quaternary: complex of protein molecule

what are the components of nucleotide?

phospharte group + sugar (ribose) + nitrogenous base (adenine)

which element is unique in proteins when comparing nucleic acids and proteins?

sulfur (absent from DNA RNA)

what is the major cell energy currency?

adenosine triphosphate (ATP)

is energy released or required when a sucrose is hydrolyzed?

it’s released

which base is only found in DNA not in RNA

thymine (T)

dna —> ATGC

rna —> AUGC

primary metabolites vs secondary metabolites

primary metabolites: sugars, lipids, proteins, nucleic acids, and carbohydrates

• found in plants

• necessary

secondary metabolites: other primary metabolies and minerals

• induced or activated for defense

what kind of secondary metabolite is Nicotine?

insectiside alkaloid (poison for higher animals)

which secondary metabolites is responsible for adding compressive strength and stiffness to the plant cell wall?

lignin

which secondary metabolites in the cell sap are responsible for the red and blue colors of many fruits and vegetables?

anthocyanin

structure of cell walls (the three layers)

1. middle lamella —> joins adjacent cells

2. primary wall → deposited while cell size is increasing; determines size/shape of the cell

3. secondary wall —> deposited after primary wall stopped growing; supports and defends; thick, cellulose, lignin

features of secondary cell walls

• deposited from the inside after the primary cell wall stopped growing

• supports and defends

• many layers

what is chromoplast?

plastid that contain carotenoids (yellow oil bodies) but lack chlorophyll

what are the features of mitochondria?

membrane-bound cellular organelles

• has an inner membrane —> cristae

• programmed cell death

• increase the surface area available to proteins

• sites of respiration

• includes: dna, rna, and ribosomes

what are the physiological functions of vacuole?

50% of the cell volume (usually in the middle)

warehouse of the cell —> lots of chemicals stored in vacuole

what are the units of microtubes and microfilaments?

microtubes —>tubulin heterodimers

microfilaments —> actin monomers

features of interphase, prophase, metaphase, anaphase, telophase, cytokinesis

interphase —> dna is replicated

prophase —> chromatin is condensed into chromosomes (longest phase)

• spindle forms

• nuclear envelope disappears

metaphase —> chromosomes line up at the equator line

• spindle microtubules attach to sister chromatids

anaphase —> sister chromatids separate and move to the poles (shortest phase)

telophase —> nuclear envelope reforms, spindle disappear

cytokinesis —> the division of cytoplasm

how are two sister chromosomes connected?

by a centromere

phragmasome and phragmoplasts

• phragmasome: sheet that separate vacuole and let nucleus move to the center for cell division

• phragmoplasts: composed of microtubules separated by two nuclei

how do O2 and CO2 get into the cell?

diffusion (high to low concentration)

how do Na+, K+ get into the cell?

through active transport of the sodium potassium pump using atp

what is osmosis and how does it work?

movement of water molecules through a selectively permeable (allowing some molecules but not others) membrane

• this is done via diffusion

what may regulate the activities of enzymes?

• temperature

• pH

• effector, inhibitor

• feedback inhibitor

what is feedback inhibition?

end product of a metabolic pathway that stops an enzyme in the earlier pathway to prevent overproduction

what is the cleavage step in glycolysis?

where glucose (6C) is partially oxidizes into two pyruvate (3C) molcules

what are the products of glycolysis?

two pyruvate molecules, two atp molecules, and two nadh molecules

when does fermentation take place and what are the products of fermentation?

in the absence of oxygen (anaerobic)

• products —> 2 ATP

how many ATP molecules are generated from each NADH produced in glycolysis and
Creb’s cycle respectively?

2 ATP - glycolysis

3 ATP - kreb’s cycle

what happened during the preparatory phase of glycolysis?

adding 2 ATP molecules to activate glucose (converting one 6-carbon glucose into two 3-carbon sugar phosphates)

where in the cell does Citric Acid Cycle occur?

the matrix of the mitochondria