unit 3 Flashcards
Understand how the invention and development of microscopes led to our understanding of cells.
The invention of the microscope led to the discovery of the cell by Hooke. While looking at cork, Hooke observed box-shaped structures, which he called “cells” as they reminded him of the cells, or rooms, in monasteries. This discovery led to the development of the classical cell theory. Microscopes have opened up many doors in science. By using Microscopes scientists, researchers and students were able to discover the existence of microorganisms, study the structure of cells and see the smallest parts of plants, animals and fungi.
What type of information can be obtained from different types of microscopes?
Light microscopes include upright compound microscopes for studying a fixed sample, inverted microscopes for viewing cell cultures or live cells, stereo microscopes to produce a 3D image and view small parts, and zoom microscopes that provide higher resolution thanks to a higher numerical aperture in the lens.
What determines (limits) the size of cells?
Cell growth is limited by rates of protein synthesis, by the folding rates of its slowest proteins, and—for large cells—by the rates of its protein diffusion.
What are two obvious differences between Prokaryotic and Eukaryotic cells?
Prokaryotes are always unicellular, while eukaryotes are often multi-celled organisms. Additionally, eukaryotic cells are more than 100 to 10,000 times larger than prokaryotic cells and are much more complex. The DNA in eukaryotes is stored within the nucleus, while DNA is stored in the cytoplasm of prokaryotes.
Describe the cell membrane
The cell membrane, also called the plasma membrane, is found in all cells and separates the interior of the cell from the outside environment. The cell membrane consists of a lipid bilayer that is semipermeable. The cell membrane regulates the transport of materials entering and exiting the cell.
What is an organelle?
An organelle is a subcellular structure that has one or more specific jobs to perform in the cell, much like an organ does in the body. Among the more important cell organelles are the nuclei, which store genetic information; mitochondria, which produce chemical energy; and ribosomes, which assemble proteins.
What are organelles found in Eukaryotic cells?
In addition to the nucleus, eukaryotic cells may contain several other types of organelles, which may include mitochondria, chloroplasts, the endoplasmic reticulum, the Golgi apparatus, and lysosomes.
Which organelles are unique to animal cells?
Centrosomes and lysosomes are found in animal cells, but do not exist within plant cells.
Which organelles are unique to plant cells?
The organelles found only in plant cells include chloroplast, cell wall and a vacuole.
What is the function of each organelle?
- Nucleus - stores genetic information
- Ribosomes - makes protein
- Plasma membrane - separates the cell from the environment
- Endoplasmic reticulum - makes proteins and lipids
- Golgi apparatus - sorts proteins
- Lysosome - breaks down unwanted material
- Mitochondria - makes energy for the cell
- Chloroplast - makes food in plant cells
- Vacuole - stores water in plant cells
- Vesicles - ships materials around the cell
- Cell wall - Rigid barrier that protects the cell
- Cytoplasm - The interior contents of the cell
- Cytosol - the gel like matrix of the cytoplasm
What is the structure and function of the endomembrane system.
The endomembrane system includes the nuclear envelope, lysosomes, vesicles, the ER, and Golgi apparatus, as well as the plasma membrane. These cellular components work together to modify, package, tag, and transport proteins and lipids that form the membranes.
What are chloroplasts? What type of cells are they found in?
Chloroplasts are the food producers of the cell. The organelles are only found in plant cells and some protists such as algae. Animal cells do not have chloroplasts. Chloroplasts work to convert light energy of the Sun into sugars that can be used by cells.
Describe the structure and function of the cytoskeleton.
The cytoskeleton of a cell is made up of microtubules, actin filaments, and intermediate filaments. These structures give the cell its shape and help organize the cell’s parts. In addition, they provide a basis for movement and cell division.
What are Cilia and Flagella and what is their function?
Cilia and flagella are cell organelles that are structurally similar but different in length and function. Cilia are present in organisms such as paramecium, while flagella can be found in bacteria and sperm cells. Cilia are shorter and more numerous than flagella.
What is the function of plasmodesmata and where in the cell do they occur?
Plasmodesmata are pathways between adjacent cells. They occur for plant cell walls.
