independent variable
controlled change
dependent variable
change that's measured
constant variable
variable that doesnt change
covalent bond
atoms share electrons
ionic bond
when atoms give/take electrons
carbohydrates
made of carbon, hydrogen, and oxygen
proteins
made of amino acids
lipids
fatty acids
nucleic acid
made of nucleotides
dehydration synthesis
Condensation reaction where molecules are connected by loss of a water molecule.
hydrolysis
when a molecule breaks down with the addition of a molecule
enzyme
speeds up a chemical reaction
active site
part of enzyme where the chemical reaction occurs/where the substrate binds to the enzyme
what happens to enzymes if the pH or temperature is off?
stops working
cell membrane
made of double layer of phospholipids
passive transport
the movement of substances across a cell membrane without the use of energy by the cell
diffusion
Movement of molecules from an area of higher concentration to an area of lower concentration.
osmosis
diffusion of water
facilitated diffusion
Movement of specific molecules across cell membranes through protein channels
active transport
the movement of materials through a cell membrane using energy
active transport proteins
move substrates against the concentration gradient
endocytosis
things going into the cell, cell engulfs material
exocytosis
release of substances out a cell by the fusion of a vesicle with the membrane.
hypertonic
Having a higher concentration of solute than another solution (cell shrinks)
hypotonic
Having a lower concentration of solute than another solution (cell swells)
Isotonic
when the concentration of two solutions is the same
transport channels
protein chanells in the cell membrane used to transport ions and molecules across the membrane
pumps in the cell membrane
made of protein
function of nucleus
Directs all the cells activities; contains the cells DNA
function of mitochondria
cellular respiration (powerhouse of the cell πͺ)
function of golgi body
package and ship proteins out of the cell
function of chloroplast
Site of photosynthesis
function of vesicles
Cellular package containing products such as protein
lysosome
kills stuff
large central vacuole
plant cells only, stores water and other liquids
prokaryotic cells
do not have a nucleus or other membrane-bound organelles
eukaryotic cells
Contain a nucleus and other organelles that are bound by membranes.
plant cells vs animal cells
cell wall, chloroplast, central vacuole vs centrioles, lysosomes
ATP
(adenosine triphosphate) main energy source that cells use for most of their work
where is the energy in ATP
between phosphate bonds
where does the energy in ATP come in during cellular respiration?
during glycolysis
what organisms do cellular respiration?
all living organisms
light dependent reaction
reactions of photosynthesis that use energy from light to produce ATP and NADPH
chlorophyll
A green pigment found in the chloroplasts of plants, algae, and some bacteria
calvin cycle
reactions of photosynthesis in which energy from ATP and NADPH is used to build high-energy compounds such as sugars
calvin cycle location
stroma
glycolysis
the breakdown of glucose by enzymes, releasing energy and pyruvic acid.
krebs cycle
second stage of cellular respiration, in which pyruvic acid is broken down into carbon dioxide in a series of energy-extracting reactions
chemosynthesis
process in which chemical energy is used to produce carbohydrates (little guys at the bottom of the ocean)
equation for photosynthesis
6CO2 + 6H2O ------> C6H12O6 + 6O2
equation for cellular respiration
C6H12O6 (glucose) + 6O2 (oxygen) ---------> 6CO2 (carbon dioxide) + 6H2O (water) + energy
fermentation
Process by which cells release energy in the absence of oxygen
product of fermentation in muscles
lactic acid
G1 phase
stage of interphase in which cell grows and performs its normal functions
S phase
DNA replication
g2 phase
The second growth phase of the cell cycle, consisting of the portion of interphase after DNA synthesis occurs.
m phase
mitosis and cytokinesis
when must dna replication occur for mitosis to occur?
synthesis
function of mitosis
Growth, Repair, Replacement, Asexual Reproduction
cytokinesis
division of the cytoplasm
g0
A nondividing state occupied by cells that have left the cell cycle, sometimes reversibly.
how do different cells differ in their rates of cell division?
some cells have longer life spans then others
why is it important for cells to have large surface area to volume ratio?
so they can be more efficient
chromatid
half of a chromosome
sister chromatids
two halfs of a chromosome
centromere
Region of a chromosome where the two sister chromatids attach
histones
protein molecules around which DNA is tightly coiled in chromatin
genes
sections of DNA that determine traits
telomeres
stoppers at the end of chromosomes
result of mitosis after cytokinesis
two identical cells
prophase
Chromosomes become visable, nuclear envelop dissolves, spindle forms
metaphase
Chromosomes line up in the middle of the cell
anaphase
the third phase of mitosis, during which the chromosome pairs separate and move toward opposite poles
telophase
the final phase of cell division in which the chromatids or chromosomes move to opposite ends of the cell and two nuclei are formed.
order of mitosis
prophase, metaphase, anaphase, telophase
external factor that controls the cell cycle
physical and chemical signals
internal factor that controls the cell cycle
cyclins and kinases
apoptis
programmed cell death
cancer
any malignant growth or tumor caused by abnormal and uncontrolled cell division
how are cancer cells different from normal cells?
they divide uncontrollably
benign tumor
a mass of abnormal cells that remains at the site of origin
malignant tumor
mass of abnormal cells resulting from uncontrolled cancer cell division
metastasis
The spread of cancer cells beyond their original site
causes of cancer
smoking, radiation, genetics, carcinogens, bad luck
cancer treatment
surgery, radiation, chemotherapy
levels of organization in multicellular organisms
cell, tissue, organ, organ system
cell differentiation
the process by which a cell becomes specialized for a specific structure or function.
how do cells differentiate?
they all use specific different genes
stem cell
unspecialized cell that can develop into a specialized cell under the right conditions
totipotent stem cells
can grow into any other cell type
pluripotent stem cells
stem cells that can become almost all types of tissues and cells in the body.
multipotent stem cells
can grow only into cells of a closely related cell family
homologous chromosomes
pair of chromosomes that are the same size, same appearance and same genes.
autosomes
non-sex chromosomes (22 pairs)
sex chromosomes
X and Y chromosomes.
haploid cells
a cell containing only one set of chromosomes - gametes (n)
diploid cells
a cell containing two sets of chromosomes (2n), one set inherited from each parent.
2n
diploid number
n
haploid number
somatic cells
body cells (diploid)