Life on Earth Flashcards
What are the common compositional themes of all living entities?
- Composed of carbon, oxygen, hydrogen, nitrogen, phosphorus, sulfur
- Contain water
- Carbon-based
Why is water important for life?
- Solvent for biological reactions
- Component of metabolic processes
Which atom is the backbone for molecules within the body?
Carbon
What are macromolecules used for?
Information, structure, metabolism
Why is carbon so important in the body?
Small, reactive, able to form chains of macromolecules and polymers
The unit of life
Cells
Define autotrophic organisms
Organisms that convert light energy into chemical energy
Plants are ________ organisms
Autotrophic
Define heterotrophic organisms
Organisms that use food molecules (generated by autotrophs) to make energy
Animals are _______ organisms
Heterotrophic
Six principles of modern cell theory
- All known living things are made up of cells
- The cell is the structural and functional unit of all living things
- All cells only arise from pre-existing cells
- Cells contain hereditary information which is passed from cell to cell during cell division
- All cells are basically the same in chemical composition
- All energy flow of life occurs within the cell
“omnis cellula e cellula”
All cells only arise from pre-existing cells
The cell is the_____________ of all living things
Structural and functional unit
DNA contains
Hereditary information
The domains of life are:
Prokaryote (Archaea and Eubacteria) and Eukaryote
Archaea and Eubacteria are
Prokaryotes
“-karyota” means
Nut/kernel
Prokaryotes are ______ celled organisms
Single-celled
Eukaryotes are _________ organisms
Multicellular
Prokaryote lack a
Nuclear membrane / Nucleus
What was the first organism?
Simple prokaryotic cell
Define Biogenesis
Scientific Theory: life arose from pre-existing life
Define Abiogenesis
Scientific Theory: life arose from non-life on earth
How old is earth?
~4.6 billion years old
What are examples of “non-living” organisms?
- Viruses
- Viroids
- Obelisks
- Prions
All life is ____
Carbon based
original old cell theory
1) cell is unit of structure
2) is a distinct entity and a building block in construction or organisms
3) cells form by free cell formation, (spontaneous generation) NO
viruses
infectious particles consisting of nucleic acid in protein/ lipid/ carbohydrate coat
viroids
infectious molecules of RNA that cause plant diseases (also in animals)
obelisks
RNA containing, virus like entities in bacteria in human GIT
prions
a transmissible abnormal form of a normally-occurring protein
anabolism
building of complex molecules from numerous simple ones
catabolism
break down of complex molecules into simple ones
list the unity of life factors (things that all life has)
- all life is cellular
- life requires input of energy (autotrophic or heterotrophic)
- life has self sustaining chemical reactions (metabolism)
- living things reproduce themselves
- info carriers for life are DNA and RNA
- life evolves (adapts); life is a continuum from first to modern forms
