The Plant Cell Flashcards
What is the general structure of eukaryotic cells?
- Plasma membrane
- Cytoplasm
- Nucleus
- Ribosomes
- Mitochondria
- Endoplasmic Reticulum
What is cyclosis?
Promotes mixing of the cytoplasm and exchange and movement of materials
How are eukaryotic cells divided into several compartments?
The DNA is combined with histone proteins located in the chromosomes in the nucleus bounded by the nuclear envelope.
What do the ribosomes do?
Link amino acids together to form protein
What is mRNA?
Messenger RNA specify the particular sequences of amino acids needed to construct different proteins
What’s the structure of the mitochondria?
Have two membranes
Inner membrane heavily folded to increase the surface area needed for respiration
What is the endoplasmic reticulum?
a communications system within the cell, channeling materials such as proteins and lipids to different parts of the cell.
What is the “rough” ER?
endoplasmic reticulum with ribosomes attached, namely polysomes for making proteins
What is the smooth ER?
no ribosomes attached, but may function in the synthesis of other things, such as lipids (e.g., for making other membranes).
What is the cytoskeleton?
comprised of microtubules and microfilaments
What are microtubules?
long, thin cylindrical structures built of protein
What are the functions of microtubules?
- Directing orderly growth of cell wall by moving cellulose-synthesizing enzymes
- Directing dictyosomes to the right places facing the cell wall
- Pulling chromosomes apart during cell division
- Directing formation of the cell plate
- Providing a road map for proteins to move around the cell
What are microfilaments?
contractile proteins. Bundles of microfilaments are believed to cause cytoplasmic streaming.
What are flagella?
thin extensions from the cell surface that contain microtubules to permit movement.
What are plastids?
Chloroplasts, chromoplasts, leucoplasts
What are chloroplasts?
contain chlorophyll and other necessary apparatus for conducting photosynthesis. They also make amino acids and fatty acids.
What are chromoplasts?
may be yellow, orange or red and impart colour to fruits or other organs (e.g., carrot roots). Red, yellow and orange bell peppers are those specific colours because of the chromoplasts in the fruit.
What are leucoplasts?
plastids that lack pigmentation and are usually for storage.
What are the two basic types of microbodies?
Glyoxysomes (plants only) and peroxisomes (in both plants and animals)
What are glyoxysomes?
convert fats into carbohydrates to be used in respiration
What do perisomes do?
play an important role in a process called photorespiration
What are oil bodies?
Blobs of oil (a type of food reserve) in the cytoplasm
What does the cell wall do?
surrounds the protoplast (the cell proper bounded by the plasma membrane and all its contents). Cell walls are living structures that play important roles in absorption, transport, secretion, digestion, and plant structure.
What phases does the plant cell walls consist of?
a crystalline phase of cellulose, embedded in a non-crystalline phase (the matrix) of pectin, extensin and often lignin (in secondary cell walls - an extra layer that is sometimes built for extra support).
What is cellulose?
Cellulose is a polysaccharide of glucose units
What does the vaculoe do?
important storage compartment for food reserves
store toxic substances
site of pigment deposition responsible for the blue, violet, purple, and dark red colours of certain flowers, fruits, and vegetables
“recycling factories” where cell components, even entire organelles, are deposited and broken down.
What does the plasma membrane do?
Bounds the living cell Mediates exchange Coordinates wall synthesis Receives and transmits hormones controls passage of materials
What is the structure of the plasma membrane?
Typical lipid bilayer with integral and peripheral proteins
What is the cytoplasm like?
Has a fluid consistency and contains numerous organelles
What are dictyosomes?
Groups of flat disk-shaped sacs involved in secretion
What does the cytoskeleton do?
Assist in construction of cell wall
Direct dicyosomes
Pull chromosomes apart
Direct formation of cell plate
What do microbodies do?
Important in photorespiration
What is division?
A cell plant separate new plant cells
Each new cell then makes a new primary wall
Old parent wall stretches and ruptures
