Cell Structure Flashcards
The literal translation of physiology is…
the study of nature or natural processes
The modern interpretation of physiology is…
the study of body functions
The literal translation of homeostasis is…
wisdom of the body
The modern meaning of homeostasis is
the bodies ability to maintain relatively stable internal conditions despite a changing environment
A negative feedback system moves a system…
toward homeostasis; stabilization
the variable returns to normal values after a disturbance
A positive feedback system moves the system…
- away from homeostasis; destabilization
- Tries to reinforce a stimulus and take the system away from a set point
- Not common in the human body
General body organization
Cells are
- the basic structural unit of a living organismm
- they vary in size, shape and function
General body organization
Tissues are
- made up of different types of cells with a common fuction
- 4 types in humans: epithelial, connective, nervous, muscle
General body organization
Organs are
- discrete structures, composed of at least two tissue types, that perform a specific function
General body organization
Organ systems are
- made of organs that work together to accomplish a common purpose
Cell structure and function
General classifications rely on
- Size: range from 7-8 microns (RBCs) to 120 microns (Purkinje fibers)
- Shape: squamous, columnar, cuboidal
- Function: exocrine, endocrine, contractile, etc.
Organells are
structures w/in a cell that have specific functions
Inclusions are
residues w/in a cell
ex. pigment granules, viruses, bacteria, glycogen (stored sugar) etc.
Membranous organelles include the following:
- nucleus
- endoplasmic reticulum
- mitochondria
- golig apparatus
- encased within a phospholipid bilayer
Non-membranous membranes include the following:
- Microtubules
- Microfiliments
- Centrioles
- Ribosomes
A micelle is…
a single layer phospholipid structure
- If the hydrophilic heads point out the medium is water
- If the hydrophobic tails point out the medium is non-polar.
The hydrophilic heads are
non-lipid soluble and polar
The hydrophobic tains are
lipid soluble and non-polar
Phospholipids move within the membrane _______ and are arranged _______.
- laterally
- asymmetrically
Cholesterol has the role of _________ of the phospholipid bilayer
stabilizing the membrane
Proteins are arranged _________ in the phospholipid bilayer.
- asymmetrically
- may span the membrane (integral/intrinsic) or exist on the inner or outer periphery (ecto- endoprotein)
The glycocalyx is
- “sugar cup”
- sugar coating to reduce friction on the surface of the cell
The intracellular region carries a _____ charge
negative
The extracellular matrix carries a ________ charge
positive
The function of the nucleus is
- contains DNA
- is the site where transcription occurs
The rough endoplasmic reticulum is
- forms proteins
- reticulum means “netting”
The smooth endoplasmic reticulum
- is the region of the cell that forms carbohydrates and lipids
The mitochondrion
is the organelle which produces ATP (energy) through the aerobic citric acid cycle (Kreb cycle)
The function of the lisosome
is to break down material in the cell
They contain powerful digestive enzymes
they are produced by the golgi apparatus
The function of the golgi apparatus is
to store and package molecules made in cell.
The cis face stores incoming material
the trans face packages and releases lysosomes
The function of microtubules is
to transport substances through the cell
it is part of the cytoskeleton
The function of the microfilaments is
to act as contractile elements
they are part of the cytoskeleton
The role of centrioles is to
guide chromosomes during mitosis
Ribosomes carry
RNA
Anabolism is
the building chemical reactions within a cell
Catabolism is the
breaking down chemical reactions in the cell
excretion is
releasing of waste products from the cell
secretion is
the releasing of synthesized molecules from a cell (mucous, proteins, hormones etc)
Mitosis is
cell division that results in two daughter cells with the same number of chromosomes as the parent cell (46)
The order of steps of mitosis is
- prophase
- metaphase
- anaphase
- telophase
- interphase
During prophase…
the nuclear membrane dissapears and chromosomes form
During metaphase
chromosomes line up at the metaphase plate
During anaphase
chromosomes move back towards the centrioles
During telephase
chromosomes approximate centrioles (cytokinesis)
the parent cell divides into two daughter cells
During interphase
the cell duplicates chromosomes in three phases
- Gap1: organelles replicate
- Synthesis: DNA duplicates
- Gap2: final protein synthesis
Mitosis occurs in order to
replace or increase tissue mass
