PBL 1: The Plant Cell Flashcards
Amyloplasts
Plastids that stores starch: considered to be leucoplasts
Proplastids
Undifferentiated young plastids common in meristematic cells.
Chloroplasts
Chlorophyll-rich plastids that carry out photosynthesis
Chromoplasts
Plastids that contain red/yellow pigments. They are located in flowers and fruits.
Leucoplasts
Colorless plastids that synthesize lipids and other materials.
Specialized function of shoot/root tip cells
Cell division: produces new protoplasm
Specialized function of epidermis cells
Water retention; cutin and wax barriers against fungi and insects
Specialized function of epidermal gland cells
Cell protection: produces poisons that prevent animals from harming plants
Specialized function of green leaf cells
Collects solar energy via photosynthesis
Specialized function of root epidermal cells
Collects water and minerals
Specialized function of vascular cells
Transports water and minerals
Specialized function of fruit cells
Produces sugars, aromas and flavourful compounds that attract fruit eating/seed dispersing animals.
Cell membrane
Found in all cells: separates the interior of the cell from the external environment. Consists of a semipermeable lipid bilayer.
They:
-regulate the passage of molecules in and out
-divides the cell into numerous compartments
-acts as surfaces that hold enzymes
Function of cell wall
-Provides strength, cellular communication and protection from chemical, fungal and bacterial attack.
Molecular components of cell wall
-Cellulose molecules crystallise into microfibrils
-Hemicellulose binds the microfibrils
-Pectin
Structural components of cell wall
-Primary cell wall (thin, flexible)
-Secondary cell wall (strengthens the primary cell wall, provides rigidity, located between primary cell wall and plasma membrane).
ONLY OCCURS IN CERTAIN CELL TYPES, E.G. tracheids, vessel elements, sclerenchyma
-Lamella: connects adjacent cells, acts like a glue, made of pectin
-Primary pit field: clustered regions of plasmodesmata
Plasmodesmata (association of cells)
Membrane channels for cellular communication, ER passes through the channel.
Function: cell signalling
-Symplastic: protoplasm of all cells of one plant connect, transport within the cells
-Apoplastic: Intercellular spaces between cells and cell wall, transport within the middle lamella is more quick and efficient
Function of Vacuole
Cell growth, digestion, storage of metabolic waste and nutrients
Components of Vacuole
-Tonoplast: vacuole membrane, selectively permeable
-Salt and Water
-Anthocyanins (water-soluble pigments)
Function of Plastids
Conducts metabolic functions including:
-Synthesis of amino acids
-Storage
-Export of specialized lipids, molecules, carbohydrates+iron
-Forms colors
Components of Plastids
-Outer+inner membrane
-Inner fluid called stroma, contains DNA and ribosomes
Etioplast
Plastid in the stage before specialising:
-Light exposure: chloroplast+chromoplast
-No light exposure: unpigmented leucoplast
Microbodies
Use and produce peroxide and contain the enzyme catalase:
-Peroxisome: peroxide used to detoxify ROS in photosynthesis
-Glyoxysome: conversion of fats to sugars
Nucleus
Stores genetic information
Components: DNA, nuclear pores, nuclear envelope
Ribosome
Protein synthesis
Components: rRNA and proteins, large and small subunit
Mitochondria
ATP synthesis
Components: matrix, inner membrane foldings (cristae), mit. DNA, double membrane
Microtubules
Cytoskeleton and motility
Components: Alpha-tubulin and beta-tubulin
Microfilaments
Structure and movement of cell
Components: Actin (protein)
