1. CELL BIOLOGY Flashcards
What does the cell theory say?
- All living organisms are composed from cells. Cells are the fundamental building blocks of every living organism.
- Cell is the smallest living structures - nothing smaller can survive.
- All cells come from preexisting cells.
How do we call organisms that consist of only one cell and how the ones made up from many cells?
Unicellural organisms, multicellural organisms.
What are common features of cells?
Membrane, geetic material, chemical reactions catalyzed by enzymes composed inside of the cell and energy system that provides the cell with energy necessary for all cell activities.
Present two cases of discrepancy in cell theory.
- Striated muscle tissue cells are uncommonly big (up to 10 cm) and have several nuclei.
- Fungi consist of narrow thread-like structures called hyphae. Hyphae are usually divided into multiple cells by septas. Some fungi, however, do not have septas. In that case hyphaes have continuous cytoplasm with many nuclei.
What can you say about the structure of unicellural organisms’ cells in comparison with multicellural organisms’ cells?
Unicellur organisms’ cells are more complex because they have to carry out all functions of life (at least 7).
What are 7 functions of life?
NUtrition, metabolism, growth, response, excretion, homeostasis, reproduction.
Define nutrition.
Obtaining food to provide energy and materials needed for cell’s growth.
Define metabolism.
Chemical reactions inside of the cell, catalyzed by enzymes produced insisde of the cell. This includes fr example cell respiration.
Define excretion.
Getting rid of watse products of metabolism.
Define growth.
Irreversibla increase in size.
Define reproduction.
Producing offspring sexually or asexually.
Define response.
The ability to react to changes in environment.
Define homeostasis.
Abillity to keep conditions inside the organism within tolerable limits.
Explain paramecius’s nutrition, metabolism and excretion.
Paramecium gathers food with the help of cilia. It is a heterotroph and so feeds on microorganisms. The food enters paramecium by endocytosis (percisely phagocytosis) through the oral groove into the cell mouth and gullet. It forms food vacuole which is joined with lysosome or digestive enzyimes that digest the content of food vacuole. digested nutriens then pass into the cytoplasm where all metabolic processes are held. Waste products of metabolism leave the cell with diffusion.
What does the contractil vacuole do?
It pumps excess water out of the cell and therefore maintains homeostasis.