Cell Structure and Function Study Guide

Cell Structure and Function Study Guide 1. What are the contributions of Robert Hooke, Anton van Leuwenhoek, Matthias Schleiden, Theodor Schwann, and Rudolph Virchow to our understanding of cells? Hooke was an English scientist who looked at cork through a compound microscope and observed tiny room-like structures that reminded him of the "cells" that monks lived in. Therefore these structures became known as cells. The cork cells where not alive so he only saw the cell wall. Anton Van Leeuwenhoek was a Dutch fabric merchant but considered himself an amateur scientist. He looked at many different things through his microscope (teeth scrapings, rainwater, blood) and observed living cells which he called "animalcules". He wrote many papers that were widely accepted by the scientific community which was unusual for a non-scholar. Matthias Schleiden was German Botanist the viewed plant parts under a microscope and discovered that plant parts are made of cells. He is considered to be the co-founder of cell theory together with Theodor Schwann, with whom he consulted. Schwann was a German Biologist who viewed animal parts under a microscope and discovered that animals were made up of cells. He extended Schleiden's cell theory in plants to animals, stating that all living things are composed of cells. Virchow was a German physician that stated that all living cells come only from other living cells. His major contribution was the idea that pathologic reactions were reactions of cells. 2. What are the three parts of the cell theory? All living things are made up of cells. Cells are the basic units of structure and function in living things. Living cells come only from other living cells. 3. How are cells, tissues, organs, organ systems, and organisms related? Be able to put them in to order from least to most complex. Cells join together to form tissues, tissues join together to form organs, organs join together to form organ systems, organ systems come together to make up an organism. Cells, tissues, organs, organ systems, and whole organisms 4. What is cell specialization (differentiation)? Specialized cells are specially designed to perform the functions for which they are intended. Each of these cell types are formed and operate differently, ensuring that the cell can carry out the necessary body function that it is intended to complete. Neurons are specialized cells that carry messages within the human brain. These cells come in an assortment of shapes and sizes. While these cells do share some similarities with other cells, they also have specialized features that enable them to complete the necessary communicative functions. 5. CELL PARTS: (the part, function, and where in the cell)  Cell (plasma) membrane-controls entry into and out of cell  Cell wall-shapes and supports a plant cell  Chlorophyll-traps light and is used to produce food for plants  Chloroplasts -food for plant cells is made here  Chromosomes-contains code which guides all cell activities  Cytoplasm-jellylike substance within cell  Endoplasmic reticulum-surface for chemical activity  Golgi bodies-stores and releases chemicals  Lysosome-digestion center  Mitochondria -"powerhouse" of cell  Nucleolus-spherical body within nucleus  Nucleus-chromosomes are found here and it is known as the brain of the cell  Ribosomes-where proteins are made  Vacuole-contains water and dissolved minerals  Centrosome- The organelle located near the nucleus in the cytoplasm that divides and migrates to opposite poles of the cell during mitosis, and is involved in the formation of mitotic spindle, assembly of microtubules, and regulation of cell cycle progression; the region pertaining to the organelle.  Nuclear Membrane- The double-layered membrane surrounding the nucleus of a eukaryotic cell, separating the nucleoplasm from the cytoplasm.  Amyloplast- A type of leucoplast found in the cytoplasm of a plant cell, and serves as storage organelle of amylopectin.

6. What is a prokaryote? All living organisms can be sorted into one of two groups depending on the fundamental structure of their cells. These two groups are the prokaryotes and the eukaryotes. Prokaryotes are organisms made up of cells that lack a cell nucleus or any membrane-encased organelles. This means the genetic material DNA in prokaryotes is not bound within a nucleus. Additionally, the DNA is less structured in prokaryotes than in eukaryotes. In prokaryotes, DNA is a single loop. In Eukaryotes, DNA is organized into chromosomes. Most prokaryotes are made up of just a single cell (unicellular) but there are a few that are made of collections of cells (multicellular). Scientists have divided the prokaryotes into two groups, the Bacteria and the Archaea. 7. What is a eukaryote? Eukaryotes are organisms made up of cells that possess a membrane-bound nucleus (that holds genetic material) as well as membrane-bound organelles. Genetic material in eukaryotes is contained within a nucleus within the cell and DNA is organized into chromosomes. Eukaryotic organisms may be multicellular or single-celled organisms. All animals are eukaryotes. Other eukaryotes include plants, fungi, and protists. 8. What organelles are found only in plant cells? Cell wall and chloroplasts 9. What organelles are found only in animal cells? Lysosomes are usually only in animal cells, but can be both. 10. What is a producer? See food web question 11. What is a consumer? See food web question How does the energy pyramid work? An energy pyramid is a graphical model of energy flow in a community. The different levels represent different groups of organisms that might compose a food chain. From the bottom-up, they are as follows: Producers bring energy from nonliving sources into the community. Primary consumers eat the producers, which makes them herbivores in most communities. Secondary consumers eat the primary consumers, which makes them carnivores. Tertiary consumers eat the secondary consumers. In some food chains, there is a fourth consumer level, and rarely, a fifth. An energy pyramid’s shape shows how the amount of useful energy that enters each level — chemical energy in the form of food — decreases as it is used by the organisms in that level. The consumers at the top of a food pyramid, as a group, thus have much less energy available to support them than those closer to the bottom. That’s why their numbers are relatively few in most communities. Eventually, the amount of useful energy left can’t support another level. That’s why energy flow is depicted in the shape of a pyramid. The energy that enters a community is ultimately lost to the living world as heat. 12. How does a food web work? Producers are plants and vegetables. Plants are at the beginning of every food chain that involves the Sun. Producers are the beginning of a simple food chain. All energy comes from the Sun and plants are the ones who make food with that energy. They use the process of photosynthesis. Plants also make loads of other nutrients for other organisms to eat. There are also photosynthetic protists that start food chains. You might find them floating on the surface of the ocean acting as food for small unicellular animals. Consumers are the next link in a food chain. There are three levels of consumers. The levels start with the organisms that eat plants. Scientists named this first group of organisms the primary consumers. They are also called herbivores. They are the plant eaters of the chain. It might be a squirrel or it might be an elk. It will be out there eating plants and fruits. It will not eat animals. Secondary consumers eat the primary consumers. A mouse might be a primary consumer and a cat might be the secondary. Secondary consumers are also called carnivores. Carnivore means "meat eater." In some ecosystems, there is a third level of consumer called the tertiary consumer (that means third level). These are consumers that eat the secondary and primary consumers. A tertiary consumer could be a wolf that eats the cat and the mouse. There are also consumers called omnivores. Omnivores can either be secondary or tertiary consumers. Humans and bears are considered omnivores: we eat meat, plants, and just about anything. The last links in the chain are the decomposers. If you die, they eat you. If you poop, they eat that. If you lose a leaf, they eat it. Whenever something that was alive dies, the decomposers get it. Decomposers break down nutrients in the dead "stuff" and return it to the soil. The producers can then use the nutrients and elements once it's in the soil. The decomposers complete the system, returning essential molecules to the producers. 13. Where is chlorophyll located? chloroplasts 14. Which organelle contains DNA ? nucleus 15. What part of the cell forms a barrier between the cell and its environment? cell membrane 16. What is cytoplasm? fluid inside the cell 17. What is smallest unit that can perform all the processes necessary for life? cell 18. What is the job of the lysosomes? digest food particles 19. What part of the cell acts as the cell’s delivery system? endoplasmic recticulum 20. What cell part supports the cell and might be made of cellulose or chitin? Cell wall 21. What cell parts carry materials between organelles such as the ER and the Golgi complex? vesicles 22. What does the Golgi complex do in a cell? It packages and distributes proteins 23. Ribosomes, the organelles that make proteins, are found on the membranes of the endoplasmic recticulum 24. Which organelle help’s to keep the cell’s membranes from collapsing? cytoskeleton