Test 1 Flashcards
What is biology?
It is the science of life (living organisms and their environment).
What is the organisation of life?
- Atom
- Molecules
- Organelles
- Cell
- Tissue
- Organ
- Organ system
- Individual
- Population
- Community
- Ecosystem
- Biosphere
What are emergent properties?
Emergent properties necessarily come from the interactions of the parts of the larger system.
What do all organisms have in common?
- Contains the same macromolecules
- Composed of at least one cell
- Grows and reproduces
- Uses energy
- Responds to their environment
- Maintains homeostasis
- Evolves and adapts
What are the macromolecules that all organisms have?
- Nucleic acids
- Proteins
- Carbohydrates
- Lipids
What is the definition of metabolism?
It is the sum of all chemical activity (growth, repair, muscles, etc.)
Where do we take our chemical energy from?
Food
What is homeostasis?
It is the ability to keep a relatively stable state of equilibrium.
What is one important mechanism of homeostasis?
Negative feedback
What is negative feedback?
Primary mechanism of homeostasis, whereby a change in a variable triggers a response that counteracts the initial change.
What are the three physiological components necessary to keep homeostasis?
- Receptors
- Control Center
- Effectors
What pathway is used to go from receptors to control center?
Afferent pathway
What pathway is used to go from control center to effector?
Efferent pathway
What system has the role of receptor in the human body?
The nervous system
What system has the role of the control center in the human body?
Nervous system
What systems have the role of effectors in the human body?
Muscular system and endocrine system
Name all organ systems
- Integumentary system
- Skeletal system
- Muscular system
- Neurons and nervous system
- Sensory system
- Endocrine system
- Cardiovascular system
- Respiratory system
- Digestive system
- Urinary system
- Reproductive system
What system is the pancreas part of?
Endocrine
What system is the heart part of?
Cardiovascular
What system are the lungs part of?
Respiratory
What system is the stomach part of?
Digestive
What system are the kidneys part of?
Urinary
What system are the testes and ovaries part of?
Reproductive
What system are the eyes part of?
Sensory
What system is the brain part of?
Nervous system
What system are the muscles part of?
Muscular
What system are the bones part of?
Skeletal
What system is the skin part of?
Integumentary
What is the cell theory?
- Cells are the smallest unit of life
- All cells come from cells
- All living organisms are made of at least one cell
What are the two types of cells?
Eukaryotic and prokaryotic
What type of cell are bacteria?
Prokaryotic
What are prokaryotes?
Simple organisms without a nucleus such as a bacteria
What are eukaryotes?
More complex organisms with a nucleus
What are the differences between eukaryotic and prokaryotic cells?
-Prokaryotic cells are 10 times smaller
-Prokaryotic cells contain less organelles; they only have ribosomes
-Prokaryotic cells do not have a nucleus to contain their genetic material (DNA)
Which type of cell specializes and adopts different shapes based on their function?
Eukaryotic
What do many cells working together form?
Tissue
What are the functions of a cell membrane?
- Maintain structural integrity of the cell
- Regulates movement of substances into and out of the cell
- Provides recognition between cells
- Enables communication between cells
- Sticks cells together to form tissues and organs
The plasma membrane is said to be…
Selctively permeable
Why does the membrane need to control what comes in and out of the cell?
Because molecules and ions concentrations must be kept constant inside the cell
What does cell recognition serve for?
It protects cells from invaders like viruses
How does the cell membrane allow cell attachment?
Cell adhesion molecules are embedded in the cell membrane and allow cell to attach
What are the main composants of the plasma membrane?
-Proteins
-Phospholipids
-Carbohydrates
-Cholesterol molecules
What are phospholipids?
They are fluids
What do phospholipids of the membrane allow?
They allow to keep the structure of the cell
What do proteins in the membrane allow?
They allow cell-recognition, cell-attachment and cell communication
What characterizes the head of the phospholipids?
Water-soluble/hydrophilic
What characterizes the tail of the phospholipids?
Fat soluble/hydrophobic
Is the outside of the membrane hydrophobic or hydrophilic?
Hydrophilic
Does the membrane let hydrophilic or hydrophobic molecules in?
Hydrophobic
What can cross the membrane?
- Small molecules
- Hydrophobic molecules
What cannot cross the membrane?
- Large hydrophilic molecules
- Charged particles
- Cells (bacteria) or viruses
What are the different mechanisms to move across the cell membrane?
-Simple diffusion (passive)
-Facilitated diffusion (passive)
-Osmosis (passive)
-With a carrier protein (active)
-Exocytosis (active)
-Endocytosis (active)
What are the two types of transport across cell membranes?
Active and passive transport
What is the definition of passive transport?
Movement of molecules that does not require energy. Generally, with their concentration gradient (high to low).
What is the definition of simple diffusion?
Movement of molecules from region of high concentration to a region of lower concentration.
What is the definition of facilitated diffusion?
Movement of substances across the cell membrane through a membrane protein.
When are carrier proteins involved in passive transport?
When a non lipid soluble molecule is transported from a high concentration area to a low concentration area.
What is the definition of osmosis?
Movement of water from a region of low concentration to a region of high concentration.
What does high concentration means?
Substance in which there is many dissolved particles ( high solute).
What does hypertonic mean?
High concentration solution
What does isotonic mean?
Equally concentrated solution