Biochemistry, Microbiology, and Immunology Weeks 1, 2 Flashcards
Why is a cell considered the basic unit of life?
Because it is the simplest structure that has all the basic characteristics of life
Atoms form to create
Molecules
Molecules form to create
Cells
Cells form to create
Living organisms
Atoms and molecules are on what level?
Chemical level
What does cell specialization mean?
Cells are diverse in their structure and function
What are tissues?
Cells of similar origin, structure, and function (group of specialized cells)
What are four types of tissues?
Epithelial, connective, muscular, nervous
What are organs?
Two or more tissues of specific form and function
What is an organ system?
Groups of organs that perform a similar function
What are the six levels of structural organization of the body?
Chemical Cellular Tissue Organ Systems Organism
Anabolism
Building up process
Catabolism
Breaking down process
What is a building up process?
Combining simple compounds to form complex compounds
What is a breaking down process?
Complex compounds broken down into simpler ones
Which metabolic system requires energy?
Anabolism
Which metabolic system releases energy?
Catabolism
Cell growth
The cell increases in size
Cell proliferation
The cell divides into identical cells
Cell differentiation
Results in specialization of cell structure and function
Atoms are composed of
Subatomic particles
Where are the subatomic particles located?
In the nucleus
Which subatomic particles are similar in mass
Protons and nuetrons
Do electrons have a mass?
Too light to matter
The columns of the periodic table of elements determines what?
How many electrons are in the valence shell
What is the atomic number?
The number of electrons
What is the atomic mass
The number of protons plus the number of neutrons inside the nucleus
The number of electrons is equal to
The number of protons
What subatomic particle is directly involved in chemical reactions between atoms
Electrons
Why do electrons have potential energy
Due to their position relative to the nucleus. The further from the nucleus, the more potential energy.
What are the different states of potential energy called?
Energy levels, or electron shells
How do electrons change shells?
By absorbing or losing energy
Where are the lower energy electrons organized in the electron cloud?
They are in the first shell/closer to the nucleus
How many electrons creates a balanced shell?
2 for the first, and 8 after that
An atom’s chemical behavior is dtermined by
What electrons are in its electron shells
Atoms with the same number of electrons in their valence shell
Exhibit similar chemical behaviors
When is an atom unreactive?
When it’s valence shell is full
What is an ionic bond?
The transfer of valence electrons from one atom to another/one molecule gives it valence electron(s) to complete the valence shell of another
What is a covalent bond?
Two atoms share the pair of valence electrons
When are ionic bonds formed?
When charged atoms attract one another
Cations have what kind of charge?
Positive
Anions have what kind of charge?
Negative
What are compounds formed by ionic bonds called?
Ionic compounds, or salts
What is an ion?
A particle that possesses a charge
What are four organic molecules?
O C H N
Are organic molecules soluble in water?
No
What kind of bonds create energy and are good for anabolic functions?
Carbon to carbon bonds
Carbon can form how many bonds?
4
Carbon carbon bonds provide:
High structural diversity, water insolubility, energy storage
What kind of bond is water?
Polar covalent
What is a polar molecule?
It has a slight charge but not quite an ion
What element is electronegative?
Oxygen
Why is water polar?
Electrons tend to stay closer to the oxygen, thus giving a partial negative charge to the oxygen atom and a partial positive charge to the hydrogen atom
What does cohesive mean?
The molecules attach to each other like glue to create high surface tension
Why is water important?
It has polar solvent properties, it is the universal solvent, many compounds dissolve in water, allowing them to travel in the body and diffuse through cell membranes, it is reactive, water molecules take part in chemical reactions
What does high specific heat mean?
Water can absorb a lot of heat energy before it gets hot itself
Due to its high specific heat, water
Is resistant to changes in temperature, absorbs large amounts of heat
Why is water important for the body?
It creates protection and lubrication; it forms a protective cushion in spaces between internal organs, in joints, and around the brain and spinal cord
How much of the body is water?
55-60%
Does an infant or senior have more water in them?
Infant
How much of water within the body is intracellular?
2/3
How much of water within the body is extracellular?
1/3
All living organisms are
complex, organized, respond to the environment, perform metabolism, able to reproduce, able to perform homeostasis, able to grow
Are viruses alive?
No because they can only perform living functions once they are inside a host and they are not all made of cells (between living and nonliving)
What is cell theory?
- All living organisms are made up of cells
- The cells are the simplest collection of matter that can live
- All cells come only from pre-existing cells
What are the two types of cells?
prokaryotic and eukaryotic cells
What is an example of prokaryotic cells?
Bacteria and Archaea
What is a prokaryotic cell?
A cell that is simple, without a nucleus or membranous organelles
What is a eukaryotic cell?
A plant or animal cell, complex, with a nucleus and membranous organelles
Are eukaryotic or prokaryotic cells larger?
Eukaryotic
Are eukraryotic or porkaryotic cells more complex?
Eukaryotic
Do prokaryotic cells have membranous structures?
No
The plasma membrane
A selective barrier for the exchange of substances between the cell and its environment
What is the cell membrane
First barrier of the cell, decides what chemicals enter/exit
What does amphipathic means?
It contains both polar and nonpolar groups
What is the lipid bilayer
The cell membrane that has a polar (hydrophilic) head and nonpolar (hydrophobic) tails
What is the nucleus
The control center of the cell
What does the nucleus contain?
The nuclear envelope, nucleolus, chromatin (genetic information)
What is the nucleolus?
Located inside the nucleus, not covered by the membrane
Where is the site of synthesis of ribosome components?
The Nucleolus
What is the canal structure surrounding the nucleus?
Endoplasmic reticulum
What is the rough endoplasmic reticulum?
The ER with the surface studded with ribosomes, it has a role in synthesis of proteins
What is the smooth endoplasmic reticulum?
It controls the movement of newly synthesized proteins to their proper locations, and to synthesize lipids
Where are the ribosomes located?
Free in the cytoplasm, on the endoplasmic reticulum
Do the ribosomes have a membrane?
No
What do the ribosomes do?
Synthesize proteins
Where do the golgi complex come from?
The rough ER
What is the golgi complex composed of?
Numerous layers forming a sac
What does the golgi complex do?
Site of protein modification, packaging and storing, sorting out (proteins destined for cell membrane or export)
What is protein modification?
Addition of chemical groups to proteins (such as sugar to glycoprotein)
Where are the proteins in the cell sent to?
Cell membrane, export or lysosomes (if they were made incorrectly)
What is the mitochondria?
The power house of the cell
What is the mitochondria composed of?
Double membrane, inner membrane forms numerous folds called cristae
Where is the site of production of energy for cells from food?
Mitochondria
What are lysosomes?
Membrane bound organelles that contain digestive enzymes in an acidic environment
What do the lysosomes do?
Destroy the ingested organisms such as bacteria, breakdown the old organelles
What is autophagy?
Death of the cell
What is a vacuole?
An organelle that stores nutrients, contains pigments to attract birds and animals, physical support, retains and degrades watse and poisons
What do the plant cells have that the animal cells don’t?
Cell wall, chloroplasts, vacuoles
What is the chloroplast?
Converts light energy into chemical energy during photosynthesis
What is the equation for photosynthesis?
CO2 + H2O + sunlight = C6H12O6 + O2 + glucose
What does the cytoskeleton do?
Provides structural shape and support and enables cellular movement
Where does exchange with the environment take place?
Cell membrane
Where do all the organelles reside?
Cytoplasm
Where are the chromosomes, genes, and DNA stored?
Nucleus
What is the protective enclosure of plant and bacterial cells?
Cell Wall
What is found in both prokaryotic and eukaryotic cells?
Ribosomes
Prokaryotic organisms lack
Organelles
Eukaryotic cells do not contain
A peptidoglycan cell wall
What are the two distinct faces of the phospholipids that make up the surface membrane of a cell?
A hydrophilic head and a hydorphobic tail, a phosphate group head and two fatty acid tails
Which cellular structure makes it possible for a cell to differ structurally and biochemically from its surroundings?
Plasma membrane
Viruses are most closely related, in that they share a common ancestor, to which domain of life?
Viruses are not considered to be part of the tree of life
Viral DNA is replicated by
Using the host’s metabolic machinery and energy
Many scientists do not consider viruses to be living organisms because
They are dependent on their host’ metabolic machinery for replication
The ____ on the surface of a virus determines which host species the virus can infect and which tissues the host species can enter
Glycoproteins
With regard to their genomes, what is one major difference between viruses and bacteria?
Viruses cannot replicated their own nucleic acids, bacteria can
