test 2 Flashcards
unicellular
composed of one cell (ex. amoeba)
multicellular
composed of many cells that may organize into tissues
organelle
specialized structures within the cell that work together to help the cell function and make proteins
list three principles of cell theory
- all living things are made of cells (although they may be uni or mulitcellular)
- cells are the basic unit of life (smallest part of an organism that is still capable of all life’s functions)
- all cells come from other cells
list the structures that differ between animal and plant cells
plant cells- central vacuole, cell wall, chloroplasts
animal cells- centrioles, flagella, lysosomes
describe the roles of proteins, lipids, and carbs in the structure of the phospholipid bilayer
protein- transport
lipids- main component of the bilayer (hydrophilic head, hydrophoic tail, selectively permeable)
carbs- structual support
why are ribosomes the most essential organelle in the cell?
they make proteins and proteins run your body (they have MANY functions)
what are three organelles that supoort the ribsome in making proteins?
rough er
-has ribsomes on its surface
-makes and packages proteins golgi apparatus
-gets vesicles of protein from the er
-processes, sorts, and ships the proteins
vesicles
-transport proteins
what is the most basic unit of life?
cells
what are two things that eukaryotes have that prokaryotes do not?
- nucleus
- membrane bound organelles
- divide/ reproduce by mitosis
how does a prokaryote reproduce?
binary fission
what is the purpose of the nucelus?
to protect the DNA
list to places ribsomes are found in the cell
- rough er
- floating in the cytoplasm
list one unique thing lysosomes do
break down dead stuff (contains enzymes that speed up chemical reactions)
if your body didn’t have vesicles what would happen?
proteins wouldn’t be able to move around the cell, so they wouldn’t be able to go to other parts of your body (a lot of things in our bodies wouldn’t work because proteins do so much)
where is DNA found in prokaryotic and eukaryotic cells?
prokaryotic- cytoplasm
eukaryotic- nucleus
which organelle helps the cell divide?
centrioles
what does the nucleuolus create?
RNA wihc makes up ribosomes
which organelle packages and modifies protiens?
golgi appartatus
list one main goal of the cell and why it is important
to make proteins, because they run your body
which organelle holds the instructions for making proteins?
nucleus
which organelle makes proteins?
ribosomes
which organelle transports proteins?
vesicles
which organelle does photosynthesis?
chloropasts
which organelle does cellular respiration?
mitochondria
which two organelles are used for movement?
flagella and cillia
what does the smooth er do?
makes lipids and detoxifies the cell
homeostasis
the need of an organism to stay stable by regulating internal conditions (ex. sweating)
solute
what gets dissolved (ex. lemonade powder)
solvent
does the dissovling (ex. water)
solution
uniform mixture of two or more substances (ex. lemonade)
concentration
amount of solute dissoved in solvent [ ]
dynamic equillibruim (in regards to homeostasis)
maintained; things in your body aren’t always the same, but they stay within a range
static equillibruim (in regards to homeostasis)
things in your body are always the same, no movement, they don’t change at all
describe the relationship between response to stimuli and homeostasis
organisms constantly take in stimuli and have to respond to them in order to maintain homeostasis (stimuli- change in enviroment, response- change in organsim as a result)
what are positive feedback loops? list two examples
output or product of a system instenstifies the response, ex. human child labor, fruit ripening
what are negative feedback loops? give two examples
output or product causes a counter response ot return to a set point, ex. human body temperature, water concentration, blood sugar regulation
what is passive transport?
requires no extra energy by cells, molecules move from high concentration to low (down concentration gradient) ex. simple or facilitated diffusion
what is active transport?
requires extra energy (ATP) to move materials, molecules move from low to high concentration (against concentration gradient) ex. endocytosis, exocytosis, molecular pumps
what is the role of the cell membrane in regulating homeostatis on a cellular level?
-controls movement of things in and out of the cell
-selectively permeable or extra picky about what goes in and out
what does and does not pass through the cell membrane easily?
does- small molecules, nonpolar, water, neutral, hydrophobic
does not- large molecules, polar
what is a hypotonic solution and what happens to a cell in one?
hypotonic- water concentration is higher than cells cytoplasm water concentration, water goes into the cell and the cell swells
what is a hypertonic solution and what happens to a cell in one?
water concentration is lower than cells cytoplasm water concentration, water goes out of the cell and cell shrivels
what is an isotonic solution and what happens to a cell in one?
identical water concentration, water goes in and out of the cell at the same rate and the cell stays the same
which organelle maintains homeostasis?
cell membrane
give an example of how your body maintains homeostasis
thermoregulation- sweating when hot, shivering when cold
what kind of molecules get through the membrane by facilitated diffusion? (need a little help)
large, polar molecules
what macromolecule helps in facilitated diffusion by acting as a tunnel?
proteins
what is osmosis?
the movement of water across the cell membrane
which organelle is critical for exocytosis and endocytosis to occur?
vesicles
what is endocytosis?
the process by which a cell takes in materials by forming a vesicle around it, active transport
what is exocytosis?
the process by which a cell exports materials out of the cell by forming a vesicle around it, active transport
what type of molecules are transported by molecular pumps?
ions
what type of molecules can’t get through the cell membrane easily?
large, charged, polar molecules
differentiaion
a process that creats special structures and functions
stem cells
undifferentiated cells that become differentiated into one or more types of specialized cells
cell cycle
a repeated pattern of growth and DNA duplication and cell division that occurs in eukaryotic cells (2 purposes- growth and repair)
chromosome
one long continous thread of DNA that consists of thousands of genes and regulatory information
gene
a section of DNA with the instructions for making a protein
sister chromatids
two identical chromatids
centromere
region of the condensed chromsomes, where spindle fibers attach
telomere
the ends of the DNA molecule
cancer
uncontrolled cell diviion, regulation of the cell cycle breaks down, divide much more often than healthy cells
metastisize
spreading of disease from one organ to others
carcinogens
cancer causing agents; chemicals that cause cancer by mutating DNA
order the formation of a human (from sperm and egg to baby)
sperm + egg
zygote
embryo
baby
what are specialized cells?
cells that have specific functions and structures that form into tissues and then organs (differentiated)
what are stem cells? (in relation to specialized cells)
cells that are not yet differentiated but will be, can differentiate into one or more types of specialized tissue
list the levels of organization from cell to organism
- cell
- tissue
- organ
- organ system
- organism
explain the key roles of checkpoints in regulaing the cell cycle
critical points where “stop” and “go” siganls can regulate the cycles (checks to make sure a specific thing is right)
explain the key roles of apoptosis in regulating the cell cycle
programmed cell death, ex. when you are first formed you have webbed fingers but those cells go through apoptosis, if a cell isn’t functioning right then instead of making more wrong cells it will die
list the phases of the cell cycle
- interphase
- mitosis
- cytokinesis
describe interphase
the growth phase of the cell cycle, longest phase
list and describe the phases of interphase
- gap 1 phase (G1)- cell grows and makes proteins
- synthesis (S)- DNA replication, doubles number of chromosomes
- gap 2 (G2)- more cell growth and protein synthesis
describe mitosis
the division phase of the cell cycle (when one cell becomes two identical daughter cells)
list and describe the phases of mitosis
- prophase- chromosomes condense and are visible
- metaphase- as sister chromtids, nuclear membrane disappears, spindle fibers form out of centrioles, spindle fibers connect to centromeres, chromosomes line up in the middle of the cell
- anaphase- sister chromatids seperate by pulling away from each other and becoming individual chromosomes, crhomtids move to opposite ends of the cell
- telophase- chromsomes decondense and start to look like chromatin again, nuclear membrane reforms around chromsomes and each pole, spindle fibers break down, cytokinesis begins
describe cytokinsesis
the division of the cytoplasm into two individual cells
nwhy is the s phase of mitosis important?
because if the number of chromsomes didn’t double then the two cells would both have only 1/2 of the DNA needed
explain the cytokinesis in a plant cell vs. an animal cell
plant- a cell plate forms midway between divided nuclei and gradually develops
animal- cells form a cleavage furrow that pinches into the cell into 2 cells
list 3 potential causes of cancer and one example of each
- biologica factors- age, genetic mutations
- lifestyle choices- diet, phycial activites
- exposures to carcinogens- tobacco smoke, asbestos
what are two places stem cells can be found?
- bone marrow
- embryos
what do osteocytes and hepatocytes produce?
osteocytes- bone (tissues)
hepatocytes- liver (tissues)
which organelle helps the cell divide?
centrioles, forms the spindle fibers
what is the cell cycle controlled by?
a chemcial control system (that starts and stops in the cell cycle- proteins, checkpoints, apoptosis, external and interal signals)
what are the two types of cell regulation?
external and internal signals
what is an internal signal?
if a cell recieves a signal from its own nucleus (to divide)
what is a tumor?
a clump of cancerous cells
what are malignant cancerous cells?
cells that spread to different organs
what are benign cancerous cells?
cells that stay contained in one place
