unit 1.1 Flashcards
Q
All cells have these 6 things:
- A cell (plasma) membrane// to separate internal environment from external
- Some sort of genetic information// arranged differently in eukaryotic and prokaryotic (all of the instructions needed for the cells activities)
- Ability to carry out chemical reactions
- Cytoplasm// where chemical (metabolic) reactions take place
- Ribosomes// locations where proteins are formed
- Own energy release system that powers all of the cells activities
Cells are?
The smallest living structures and building blocks of life, as nothing smaller exists
what are the 3 atypical example cells?
- Striated muscle fibers (type of tissue we use to change the position of our body)
- Fungal hypha (
- Giant algae
Explain Striated Muscle Fibres…
- Striated muscle fiber cell:
Much larger than other cells (30 mm in length)
Contain several hundred nuclei
Explain Fungal Hypha
Cell that has a tube like structures
Many nuclei
Explain giant algae…
- Simpler in structure and organization that in plants
basis of many marines in food chains
They can get really big in size (up to 100 mm in length)
unicellular
contain only one nucleus.
feed themselves via photosynthesis
Explain the main concept of the cell theory
“All living things are made up of one or more cells” - main concept
Cells are the smallest unit of life
Cells come from pre-exisitng cells
Exceptions to the cell theory…
Most living organisms consist of cells, except for a few organisms or parts of an organism that do not consist of typical cells
What is the technical terms for exceptions to the theory
Discrepancies - the exceptions in the theory or general trend
What are unicellular organisms?
Organisms consisting of only one cell yet carry out all functions of life in that cell
unicellular organisms carry out…
7 main functions:
Nutrition - obtaining food to provide energy and the materials needed for growth
Reproduction - Producing offspring either sexually/asexually
Metabolism - Chemical reactions inside the cell, including cell respiration to release energy
Growth - an irreversible increase in size
Response- the ability to react to changes in the new environment
Excretion - Getting rid of waste products of metabolism
Homeostasis - keeping conditions inside the organism within tolerable limits
What was an important part of the cell theory? *historically
The development of the microscope was an important tool to analyze and understand whats going on with cells at a smaller level
(1635-1703) Robert Hooke - first to use the term ‘cell,’ using microscopes to look at cork (wine bottle corks)
Lewin HooKE - Officially discovered cells and observed single celled organisms
Receives most of the credit (1632-1723)
What
is a prokaryotic cell??
have a cell wall outside the membrane
full of an uninterrupted chamber of cytoplasm, due to no nucleus existing
contains a nuclei (an area of the cell which contains DNA but is not a true nucleus)
What is a eukaryotic cell?
organelles are present in the cytoplasm of eukaryotic cells that are analogous to the organs of multi-cellular organisms in that they are distinct structures with specialized functions
Why does SURFACE AREA AND VOLUME matter in a cell?
The rate at which a substance crosses a membrane depends on it surface area
The rate of reactions is proportional to the volume of the cell
(If the ratio is too small substances will not enter as quickly, as waste needs to be removed and there becomes a problem removing and expelling wastes from the cell)
