Bot 20_Lec 1_Review of Important Concepts in Plant Physiology

basically, what is the study of plant physiology?

study of plant functions

three dynamic processes that account for plant life that is studied in plant physiology

plant growth, metabolism, reproduction

what is crop physiology?

an applied field of plant physiology involving study of plant func in genetically similar plants cultivated in the same loc

enumerate the four cited importance of plant physiology

1. efficient use of nutrients

2. coping w/ biotic & abiotic stresses

3. increase crop yield thru plant growth regulators

4. improve food & feed quality

describe the evolution of plants (bryophytes, ferns, gymnosperms, angiosperms)

1. bryophyte: has no vascular system, transport is thru diffusion, seedless

2. fern: has vascular system, reproduce thru spores

3. gymnosperms: has naked seeds, has vascular system

4. angiosperms: flowering plants, has enclosed seeds, has vascular system

TRUE or FALSE. ferns require water for fertilization

true

under the four "groups" in the previous card, in which category do most plants nowadays fall under?

angiosperms

four basic requirements of plant life

light, CO2, water, minerals

generally, what is the principle of the loc of plant organs to its function?

the location is proportional or may connect para macarry out ng organ yung function niya

two main organ system of plants

root and shoot system

enumerate and describe the three plant cell types

1. parenchyma

- has very thin primary wall

- origin of the 2 other cell types; changes thru differentiation

- has protoplast/alive

2. collenchyma

- has semi-thick primary + secondary wall

- has protoplast

3. sclerenchyma

- has secondary wall so very thick

- dead/no protoplast; HOLLOW INSIDES

describe the functions of the three types of cell

1. parenchyma

- storage and basic metabolism

2. collenchyma

- flexible support

3. sclerenchyma

- support and strengthen non extending regions of plant (e.g., mature stems)

among the three types of cells, which is considered the generic plant cell?

parenchyma cell

collenchyma cells are also termed as the _______ cells.

glue

in what state of organs are collenchyma cells found?

in growing shoots, stems, & leaves

describe the two subtypes of sclerenchyma cells

1. fibers

- long, slender, occur in strands

- ex. cotton, hemp, linen

2. sclerids

- short, varying shape, in groups

- gristle in pears

what gives rise to plant organs?

tissue systems

describe the plant tissue system in every plant organ

- dermal tissue on the outermost, then ground tissue, and innnermost is vascular tissue

- ground tissue is the major part of every organ

- the same yung general arrangement nung tissues but different lang ang shape and placement

describe the functions of the different plant tissue systems

1. ground tissue

- photosynthesis, storage, structural support

2. vascular tissue

- distributes nutrients

- composed of xylem and phloem

3. dermal tissue

- covers & protects exposed plant surfaces

in ground tissues, what cell type makes up most primary growth?

parenchyma cells

vascular tissues: differentiate the func of the xylem and the phloem

1. xylem - carries water & ions thru the plant

2. phloem - sugars & other solutes

two components that make up the

1. xylem

2. phloem

1. tracheids, vessel members

2. sieve tubes, companion cells

dermal tissues: describe and give the func of the epidermis and periderm

1. epidermis

- single outer layer of cells

- secretes waxy, protective cuticle

- contain special gas that FORMS STOMATA

2. periderm

- replaces the epidermis in woody stems & roots

three types of meristems

1. apical meristem

2. lateral meristem

3. intercalary meristem

apical meristem: general description & function

- types: shoot and root apical meristems

- found at the tips of roots & shoots

- increase plant length

apical meristems: what are the three primary meristems that apical meristems give rise to? what are the purpose of each primary meristems?

1. ground - give rise to ground tissues

2. protoderm - give rise to skin coverings

3. procambium - give rise to plumbing of plant

lateral meristems: describe the function of lateral meristems

- for secondary growth

- add girth/width by producing wood and bark

intercalary meristems: general description & function

- substitute to lateral meristems in species that don't have it like grasses

- the intercalary meristems add length to the plant

three vegetative organs of plants

roots, stems, leaves

what are the functions of roots?

1. plant anchor

2. mineral & water absorption from soil

3. storage

what part of the root particularly absorbs water and minerals?

root hairs

describe the arrangement of the three zones of the roots

(top to bottom)

- zone of maturation

- zone of elongation

- zone of cell division

function of stems

1. support leaves to maximize light absorption

2. part of the channel for transporting water, minerals and organic solutes

3. for storage

describe the stem structure of woody dicots in comparison to a monocot stem

discrete vascular bundles replaced by continuous xylem rings

TRUE or FALSE. stems form tree rings

TRUE

function of the leaves

main photosynthetic structure

3 parts of leaves

blade, petiole, pair of stipule

key diff of a plant cell with animal cell

1. plant cell has cell wall, animal cell has none

2. plant cell has one large central vacuole instead of various dispersed ones like in animal cell

3. plant cell has chloroplast, animal cell has none

describe the functions of these organelles: Rough ER, Smooth ER, and Golgi Apparatus

1. rough ER - protein synthesis

2. smooth ER - lipid synthesis

3. Golgi Apparatus - further processing of proteins

describe the functions of these organelles: peroxisome, glyoxysomes

1. peroxisome - breakdown of H peroxide and other toxin

2. glyoxysomes - break down fats

describe the func of the cytoskeleton

provide structure
allow movement of cell
internal movement of cell structure

describe the cell wall and cite its functions

1. func: protection from pathogen attack

2. func: enables plant expansion as the vacuole expands

3. has the middle lamella, primary wall, secondary wall as the layers

4. made up of cellulose + other polysaccharides

what is the biomolecule that makes the cell wall (and xylem) thick?

lignin

describe what is the plasmodesma

the space between "cells" of the cell wall that allows easier transport from one cell to another

describe the plasma membrane along with its functions

1. a phospholipid bilayer with embedded proteins

2. func: selective permeability to substances

3. has carbohydrates as identification tanks

cell membrane: two types of cell membrane protein

1. peripheral- loc on one side of the membrane

2. integral- bypass the layer, or mas matangkad siya dun sa bilayer genorn

cell membrane: permeability of substances

permeable: small hydrophobic and small uncharged polar

nonpermeable: larger uncharged polar and ions

cell membrane: how do the substances that are not allowed by the lipid bilayer to enter (but are necessitated by the cell) able to enter the cell?

thru protein transporters (based sa diagram parang integral proteins)

cell membrane: other function of embedded proteins in the lipid bilayer

receptors

cell membrane: what does the Fluid Mosaic Model tell?

that the phospholipid and the proteins are not rigid and can move

describe the function of the nucleus

- the ctrl center

- stores genetic info in chromosomes

define what is a genome

refers to all the genetic material in the cell

what is the function of nuclear pores?

passageway sa nucleus and cytoplasm

describe the evolution of the eukaryotic cell: the Endosymbiotic Hypothesis

- the eukaryotic cell (w/o mitochondria, plastid, chloroplast), mitochondria and chloroplast arose separately. the "eukaryotic cell" engulfed a bacteria (mitochondria, plastid chloroplast), but it cannot digest it

- these formed endosymbiosis rather with the rest of the eukaryotic cell

- these engulfed bacteria retained their own DNA

describe the function of the mitochondria

ATP production thru respiration: powerhouse of cell

three pigment groups and their descriptions

1. chloroplast

- green pigment that require light

- photosynthesis

2. amyloplast

- starch storage

- colorless

3. chromoplast

- carotenoid (red and yellow)

- colors of petals, fruits

TRUE or FALSE: chloroplasts are easily degraded to chromoplasts

TRUE

describe the three function of plant vacuoles

1. storage of water, ions, nutrients

2. waste product receptacle

3. regulates turgor pressure

what is energy?

capacity to do work (cell work in the context of the subj)

two forms of energy

- potential: energy that is stored/energy at rest

- kinetic: energy in motion

first and second law of thermodynamics

- first law: energy is constant; so energy cannot be created nor destroyed

- second law: natural tendency of the universe is towards increasing disorder

what is entropy?

degree of randomness

what do you mean by spontaneous rxns?

can occur without input of external energy

what is enthalpy?

total energy content of a system

define what is the Gibbs Free Energy

quantitative expression/ measure of energy for the performance of work

Gibbs Free Energy formula

d = delta

H = enthalpy

S = entropy

T = temperature

dG = dH - TdS

two types of reactions accdg to energy requirement and the value of their dG

exergonic (- dG)

endergonic (+ dG)

interpretation of the dG value

(-) exergonic, spontaneous

(+) endergonic, non-spontaneous

anabolic vs catabolic pathways

catabolic: break down complex substrates into simple end products

anabolic: synthesize complex end products from simple substrates

what is energy coupling?

the products of catabolic processes are used to drive anabolic processes, which are energy-requiring

three properties of enzymes

specificity, catalytic efficiency, (mostly) reversible

describe enzyme composition

protein + non protein component

non protein component

- can be prosthetic grp or cofactor

1. prosthetic grp: tightly bound organic molecule

2. cofactor: not tightly bound but transiently associated w/ protein

cofactor can be:

1. metal activator: metal ion

2. coenzyme: organic

two sub-components of the active site

binding site, catalytic group

what allows enzyme specificity?

its uniquely-shaped active sitet

four successive levels of enzyme structure + description

1. primary: AA sequence

2. secondary: held by H-bond

3. tertiary: 3d shape

4. quaternary: association of subunits

notes on mechanism of enzyme axn

- E + S --> E-S --> E + P

- enzyme lowers activation energy

two important parameters in enzyme kinetic + description

- Vmax: maximum enzyme act

- Km: substrate concentration in mol when 1/2 vmax is reached

two mechanisms of inhibition of enzyme activity + descriptions

1. active site directed inhibition: inhibitors compete with substrates for the binding site

2. non-active site directed inhibition: change shape of active site by binding to enzyme elsewhere on the enzyme

explain the effect of temperature and pH on enzyme activity

both na sa middle ang optimal range

describe the effect of substrate conc. on enzyme activity

increasing siya but nagpaplateau at some point kasi enzyme active site limitation na so ket iincrease substrate wala nang available sites for rxn catalysis

four forms of regulation of enzyme activity

- gene expression

- compartmentation

- covalent modification

- feedback inhibition