Plant Cells & Tissues

Prokaryotes

consists of archaea and bacteria kingdoms

-single strand of DNA in neucleoid region

-usually smaller than eukaryotes

-usually single-celled

-may not need O2

-no membrane-bounded organelles

Eukaryotes

-membrane-bound neucleous

-usually larger than prokaryotes

-usually multicellular

-needs O2

-has membrane-bounded organelles

Cell Theory

cells are the basic units of life

all living things are made up of cells- either in a single cell or many

all cells come from other cells, and all cells are linked to the first cells

Plasma Membrane

outer boundary of the protoplasm of a cell that is composed of phospholipid bilayer

Nucleus and It Parts

“control center of the cell” found within nuclear envelope

nucleolus: contains RNA and protein

Endoplasmic Reticulum

complex system of interlinked, double-membrane channels subdividing cytoplasm of cell, some of it is studded with ribosomes (site of protein synthesis)

Dictyosomes

organelle used in synthesis of materials by the cell

Mitochondria

organelle that is the center of the citric acid (Krebs) cycle and the electron transport chain of aerobic respiration; the “powerhouse of the cell”

Peroxisomes and Glyoxisomes

pero: breaks down toxic substances and participates in photorespiration in plants

glyo: converts fats into sugars

Vacuoles

pocket of fluid that functions as storage

Cytoskeleton

involved in movement within a cell and in a cell’s architecture; constructed mainly of microtubules and microfilaments

Plastids

organelle primarily associated with storage or manufacture of carbohydrates (e.g. leucoplast, chloroplast)

Leucoplasts

non-pigmented (colorless) plastid associated with starch accumulation/storage

include amyloplasts (starch synthesizers) and elaioplasts (oil synthesizer)

Elaioplasts

a type of leucoplast (storage plastid) that stores lipids/oils

Tannosomes

a plastid that produces tannins, which are found in grape skins and oaks

Proteinoplasts

a leucoplast that contains stores proteins; found in seeds and nuts

Chromoplasts

a plastid that contains pigments (not including chlorophyll) that are yellow, red, or orange; the pigment can attract pollinators

Chloroplasts

a plastid that contains chlorophyll (green pigment); site of photosynthesis in photosynthetic organisms

Chloroplast Anatomy

grana: series of stacked thylakoids (singular granum)

thylakoid: coin-shaped membranes that contain chlorophyll; where first steps of photosynthesis happen

chlorophyll: green pigment essential to photosynthesis

stroma: fluid portion of chloroplast that contains enzymes used in photosynthesis

Endosymbiotic Theory

theory that states chloroplasts and mitochondria were once independent organisms; theory says an ancestral bacterium may have absorbed/eaten the organelle and then lived symbiotically

Plant Tissues

groups of cells performing a similar function; roots, stems, leaves, and flowers are made from tissues

Parenchyma

thin-walled tissues that store lipids, starches, pigments, crystals, tannins, and other secretions

Chlorenchyma

tissue composed of parenchyma cells that contain chloroplast

Collenchyma

tissue composed of cells with unevenly thickened walls that provide flexible support; found in celery

Sclerenchyma

tissue composed of lignified cells with thick walls that functions primarily to strengthen and support plant; found in seed coats, nut shells, and pits