Introduction to cells Flashcards
Define trend
A prevailing tendency, a generalization.
Define discrepancy
Does not fit the general trend, a variation from the trend.
What does a trend lead to?
They lead to the development of predictions of what we expect to observe.
What does a discrepancy lead to?
They cause trends to lead to scientific questions.
According to cell theory (1)
Every living cell is surrounded by a membrane, which separates the contents from the surroundings.
According to cell theory (2)
Cells contain genetic material, which contains the instructions for the cells activities, many are chemical reactions catalysed by enzymes.
According to cell theory (3)
Cells have their own energy release system.
The three parts of the cell theory are:
- The cell is the basic unit of life.
- All living things are composed of cells.
- Cells come from preexisting cells.
What is metabolism?
Metabolism is the sum of all the chemical reactions in a cell.
What is an anabolic reaction?
Anabolic reactions use energy. They are endergonic. In an anabolic reaction small molecules join to make larger ones.
What is a catabolic reaction?
Catabolic reactions release energy. They are exergonic. In a catabolic reaction large molecules are broken down into smaller ones.
What is sensitivity?
Even single celled organisms can recognize what is going on around them, and respond to changes in the environment.
2 main ideas of excretion
- All organisms use a source of energy for their metabolic activities.
- All organisms excrete metabolic waste matter
What is homoteasis?
Living organisms keep their internal environments within a certain range (they maintain a stable internal condition), despite changes in their external environment.
Funcional characteristics of life
- Cellular structure
- Nutrition
- Reproduction
- Metabolism
- Growth
- Sensitivity
- Homeostasis
- Excretion
What are stem cells?
A stem cell is essentially the building block of the human body. Stem cells are capable of dividing for long periods of time, are unspecialized, but can develop into specialized cells. The earliest stem cells in the human body are those found in the human embryo. The stem cells inside an embryo will eventually give rise to every cell, tissue and organ in the fetus’s body.
Difference of regular cell and stem cell
Unlike a regular cell, which can only replicate to create more of its own kind of cell, a stem cell is pluripotent. When it divides, it can make any one of the 220 different cells in the human body. Stem cells also have the capability to self-renew – they can reproduce themselves many times over.
Two types of stem cells
Embryonic stem cells - Embryonic stem cells include those found within the embryo, the fetus or the umbilical cord blood.
Adult stem cells - Adult stem cells can be found in infants, children and adults. They reside in already developed tissues such as those of the heart, brain and kidney.
