Chapter 2 test part 1 October 2 and 3 Flashcards
define theory
the accepted explanation for what we observe in nature
prokaryote
single-celled organism that lacks a nucleus and other membrane-bound organelles.
eukaryote
organism that has cells containing a nucleus and other membrane-bound organelles.
semipermeable/ selectively permeable
only certain molecules can cross the cell membrane
fluid mosaic model
model proposes that integral membrane proteins are embedded in the phospholipid bilayer, and that the membrane is in a constant change, behaving like a fluid, rather than a solid.
peripheral membrane protein
a protein that is only temporarily associated with the cell membrane and can be easily removed.
intergral membrane protein
protein that is permanently embedded within the cell membrane; a range of important functions including transporting molecules across the membrane.
know how to calculate surface to volume ration
cytosol
watery substance that makes up cytoplasm, and contains other cell structures such as ribosomes.
cytoplasm
material inside the cell membrane, including the watery cytosol and other cell structures except the nucleus if one is present.
nucleus
membrane- enclosed organelle found in most cells
nucleolus
non-membrane bound organelle found in the nucleus of many cells and is mainly involved in the assembly of ribosomes.
nuclear pore
tiny hole in the nuclear envelope that helps regulate the exchange of materials between the nucleus and the cytoplasm.
gene
segments of the DNA that code proteins
chromatin
DNA coiled around proteins and gently twisted
chromosome
Chromatin tightly twisted
diffusion
the movement of molecules from areas of HIGH concentration to areas of LOW concentration
osmosis
diffusion of water from an area of HIGH concentration to an area of LOW concentration
facilitated diffusion
passive transport of a substance through a membrane with the help of transport proteins.
pinocytosis
occurs when the cell membrane folds inward to form a channel allowing dissolved substances to enter the cell; also known as cellular drinking, the liquid that enters the cell is encircled within a pinocytic vesicle.
phagocytosis
process in which pathogens and dead cells are consumed and destroyed by a phagocyte; also known as cellular eating, occurs when the cell membrane engulfs solid material, forming a phagocytic vesicle which then enters the cell.
what is the cell theory
- All living things are made up of at least one cell
- In the 1800’s they also discovered that cells are the basic unit of structure and function in living things
- Cells only come from other existing cells.
- Also explains why things are living and not living
who is Leeuwenhoek
improved the microscope and made even more discoveries
who is virchow
observed that cells divide to produce more cells an that all cells arise only from other cells.
who is Schwann
German scientist who suggested that cells were the basic unit of structure and function of all life.
Who is Hooke
named the small structures seen under a microscope
what are structures common to all cells
all cells are very small, plasma membrane, cytoplasm, ribosomes, cytoskeleton, and DNA
Features and characteristics of prokaryotic cells
Do NOT contain a nucleus or other membrane bound organelles.
Usually smaller than eukaryotic cells.
Evolved 3.5 billion years ago
Include ONLY bacteria.
Features and characteristics of eukaryotic cells
Contain a nucleus and possibly other membrane bound organelles.
Usually larger cells
Evolved 2.5 billion years ago from prokaryotic cells
Include all living things OTHER THAN bacteria.
What are various names for the cell membrane
phospholipid bilayer, plasma membrane, cell membrane
functions of the cell membrane
provides a boundary between the inside and outside of the cell, protects and supports the cell, and regulates what can pass through.
why do some substances need to use a membrane protein?
larger or polar molecules cannot cross the membrane on their own and need help
what is the function of integral proteins
Permanently embedded within the membrane.
Channel proteins
Transport proteins
Receptor proteins
Adhesion proteins
Identification proteins
What is the function of peripheral proteins
Temporarily associated with the cell membrane.
Often associated with integral proteins such as ion channels or receptor proteins.
Most are hydrophilic, so they cannot exist near the fatty acid tails layer.
Make sure you know how to label the picture
what is included in the cytoplasm
space inside the cell membrane, not including the nucleus. This space is filled with the cytosol, other molecules, and organelles.
What are the three varieties of cytoskeletal fibers
Microtubules
Microfilaments
Intermediate filaments
What is the structure of the nucleus
DNA is maintained in a double membrane organelle, the nucleus
What is the function of the nucleus
able to regulate the expression of of genes and control the process that occur in a cell.
Where are ribosomes found
bound to the endoplasmic reticulum or nucleus, or floating free in the cytosol.
where are mitochondria found
found in cells of eukaryotic organisms
Structure of a ribosome
Each ribosome is composed of a large subunit and a small subunit (made in the nucleolus).
structure of mitochondria
surrounded by a double membrane system
function of ribosomes
use mRNA to build a chain of amino acids in a process called translation.
function of mitochondria
are the site of cellular respiration (aka. powerhouse of the cell).
make sure you can label the mitochondria and ribosomes picture on the study guide
function of the chloroplast
produce energy through photosynthesis
function of the ribosome
make proteins
function of the rough endoplasmic reticulum
Transport vesicles bubble off of the Rough ER and carry protein to the Golgi apparatus.
function of the smooth endoplasmic reticulum
Lipid synthesis
Calcium ion storage
Drug detoxification
function of the golgi complex
Modifies, sorts, and packages the proteins made in the RER so they can be transported where they are needed.
function of the vesicles
Use for metabolism, transport, and storage of molecules.
function of the centrioles
used in cell division
make sure you can label the image for cell structure
As you increase in complexity, new abilities arise.
emergent properties
Level of organization in multicellular organisms
organelle, cell, tissue, organ, organ system, organism
What is the colonial theory
Cells toward the “front” have more developed eyespots then cells toward the “back”. Allowing the colony to swim forward toward the light.
what are colonial organisms
single celled creatures that live and work together.
what is the concentration gradient
the difference in the concentrations of molecules across a membrane.
What are membrane proteins
proteins attached or associated to a cellular membrane
what is facilitated diffusion
Diffusion of a molecule through a transport protein WITHOUT the use of energy.
GO OVER DIFFUSION AND READ CK12
be able to determine what direction water will move in a given situation in osmosis
what is the evolutionary adaptation for osmosis
To regulate water concentrations, some single celled organisms contain a contractile vacuole.
Once filled, the vacuole will contract and force excess water out of the cell.
this is an adaptation to living in fresh water
what is the energy source used in active transport
ATP
What biomolecule is involved in active transport
glucose or amino acids
What way does active transport move molecules
against the concentration gradient
What body system is the sodium potassium pump essential?
cardiac muscle, kidney function, and nerve signaling
what is the basic process of the sodium potassium pump
Three sodium ions bind with the protein pump
Carrier protein gets energy from ATP
Two potassium ions from outside the cell bind to the protein pump
Potassium ions are transported into the cell and process repeats
whats the goal of endo and exocytosis
endocytosis takes substances in and to the cell membrane
Exocytosis shifts materials such as waste products from inside the cell and pushes them out
how does endocytosis work
the membrane folds over the substance and becomes completely enclosed by the membrane and it gets pinched off by the vesicle into the cytosol
how does exocytosis work
vesicles fuse with the plasma membrane releasing the contents to the outside of the cell
do exo and endocytosis require energy
Yes and it comes from the cell
