chapter 2 Flashcards
enzymes
biological catalyst
are proteins, denaturation
enzyme functions
speed up the rate of a biochemical reaction by lowering the energy of activation
they are specific (will catalyze specific reactions)
energy
the capacity to do work. it cant be created or destroyed it can only change its form
metabolism
a process where energy is generated & expanded
two types of metabolic process
catabolism & anabolism
catabolism
degradative (breaks down)
anabolism
synthetic (breaks up)
reactants (substrates)
substances that enter the reactions
intermediates
compounds formed between the start & end of a pathway
products
substances present at the end of a pathway
photosynthesis
a process where carbon dioxide & water make sugar (anabolic reaction)
where does photosynthesis occur?
thylakoid membrane which are found in the chloroplasts
3 stages of photosynthesis
capturing of energy from sunlight
using sunlight energy to make atp & nadph
using atp & nadph to convert CO2 into glucose
2 phases of photosynthesis
light dependent reactions
during this phase, light energy is converted into atp & water is split to release O2
requirements for photosynthesis
sunlight, water, adp, nadp+, chlorophyll, electron acceptors
photolysis
using sunlight to break down water
light dependent reactions
cO2 is converted to glucose
requirements- atp, nadph, co2, RUBP (5 carbon molecule)
light independent reactions
press or convert co2 into glucose
adp & nadp+ are regenerated to be used in the light dependent reaction & the cycle begins again
two types of cellular respiration
anaerobic
aerobic
anaerobic
occurs in the absence of oxygen
aerobic
occurs in the presence of oxygen
when does the cell need energy?
based on levels on atp
when levels of atp are high….
cellular respiration is low
when levels of adp are high….
cellular respiration is moderate
when levels of amp are high….
cellular respiration is high
where does cellular respiration occur?
mitochondria
structure - double membrate structure (cytoplasm)
aerobic respiration
C6H12O6+6O2—>6CO2+^H2O+38 moles of ATP
(beginning products of photosynthesis)
cellular respiration takes place in 4 stages
glycolysis, transitional phase, kreb cycle & electron transport chain
glycolysis
takes place in the cytoplasm of cell. converts glucose to pyruvate
transitional phase
takes place in the cytoplasm. converts pyruvate to acetyl CoA
kreb cycle
takes place in the matrix of the mitochondria. converts acetyl CoA to nadh & fadh2 (energy yielding compounds)
energy transport chain
found on the inner mitochondria membrane converts nadh & fadh2 to atp
conversion rate
1 nadh- 3 atp’s
1 fadh2= 2 atp’s
glycolysis
- divided into 2 phases: preparatory & pay-off
-glycolysis means splitting of sugar
-cells mist invest two atp molecules in this process
end products : 2nadph, 4 atp, 2 pyruvate, -2 atp
transition phase
pyruvate is converted to acetyl CoA
end products: 2 acetyl CoA +2 CO2 +2NADH
kreb cycle
acetyle CoA is converted to NADH & FADH2
end products:6 NADH 2 atp 2fadh2
electron transport chain
the nadh’s & fadh2’s made in the kreb cycle are now converted to atp
plasma membrane
permits the flow of molecules across the membrane & contains receptors that can affect the cells activities
nucleus or nucleus region
all cells have a region that localized the DNA which can be copied, read & passed onto offspring
cytoplasm
all cells have a cytoplasm that contains membrane systems, particles, filaments & a semi-fluid substance
simple diffusion
small, non-polar molecules move freely across the membrane. direction of movement: high amounts–>low amounts
passive transport (facilitated diffusion)
the movement of any substance through a membrane. the movement is from high concentration to low concentration without using energy (requires a carrier)
active transport
the movement of water. it is a type of passive movement where water moves from an area of higher concentration to an area of lower concentration
osmosis
the movement of water. water movers from high concentration to lower concentration
hypotonic fluid
has a lower concentration of solute than fluid in the cell. water will then move into the cell & cause the cell to burst
hypertonic fluid
a greater concentration of solute than the fluid in the cell. water will move out & cause cell to shrink
isotonic fluid
same concentration of solute as the fluid in the cell. the concentration of water is equal so theres no movement of water
exocytosis
A process that move substance enclosed in small sacs from the interior portion of the cell to the outside
endocytosis
a process that moves substances enclosed in small sacs from the outside to the inside of the cell
pintocytosis
cell drinking
phagocytosis
cell eating
cell membrane
forms a continuous boundary layer around the cell. known as gatekeeper of cell.
peripheral membrane
proteins are loosely associated with the membrane
transmembrane
proteins span the length of the membrane
nucleus
brain of the cell. houses genetic information & isolates dna from the rest of the cell
nucleolus
found within the nucleus where subunits of ribosomes are made
endoplasmic reticulum
a collection of interconnected tubes & flattened sacs that begin at the cytoplasm
rough endoplasmic reticulum (RER)
rough in appearance & are the site of protein synthesis
smooth endoplasmic reticulum (SER)
no ribosomes. site of lipid synthesis
golgi
post office of cell
lyosomes
house keepers of the cell
peroxisomes
vesicles containing enzymes that break down fatty acids & amino acids (specific housekeepers)
mitochondria
power house of the cell. site of cellular respiration
cilia, flagella & pseudopods
provide locomotion for the cell (movement)
cytoskeleton
gives the cells their shape
vacuoles
storage of food
chloroplasts
site of photosynthesis
cell wall
provides protection for the cell membrane
cell cycle
s recurring sequence of events that extend from the time the cell forms until it dies
G1-growth
period where proteins, carbohydrates & lipids are needed by the cells made. also where its determined if a cell will cycle or die
G0
where cells go to die
restrictive point
where cell is checked for successful completion of protein, carbohydrate & lipid synthesis
S phase
where DNA is synthesized or copied
G2
where everything that is needed for mitosis is made
M phase (mitosis)
period of cell division
the 4 phases
prophase, metaphase, anaphase, telophase
PMAT
mitosis
division of somatic cells. end product will be genetically identical cells
somatic cells
non-sex cells
chromosome
physical structure which housed DNA
chromatid
1/2 of a chromosome aka daughter chromosome. contains 1/2 of genetic information
chromosome number
tells how many of each type of chromosome is present in a cell
diploid 2N
has 2 copies
Haploid 1N
has 1 copy
tetraploid 4N
has 4 copies
G1, G2, & S are known as…
interphase. most metabolically active part of the cell cycle
prophase
chromosomes are short & thick. nuclear membrane begins to disappear. spindle fiber forms
metaphase
nuclear membrane completely disappears. chromosomes line up on equatorial place (middle of cell)
anaphase
division of cytoplasm begins. chromosome pull apart & chromatids go to opposite side of cell
telaphase
cytokinesis is completed. nuclear membrane reforms
end result: 2 genetically identical cells
meiosis
reduction division
occurs in 2 stages & in sex cells
homologous chromosomes
chromosomes with same genetic information
synapsis
2 homologous chromosomes are joined together
crossing over
exchange of genetic information between synapsed chromosome
bivalent
2 synapsed chromosomes
tetrad
4 synapsed chromatids
sister chromatids
chromatids from different chromosomes
non-sister chromatids
chromatids from different chromosomes
prophase 1
nucleic membrane begins to disappear chromosomes are short & thick spindle fibers form homologous chromosomes synapse crossing over occurs
metaphase 1
nuclear membrane has completely disappeared
homologous chromosome line up on equatorial plane
anaphase 1
cytokinesis begins
homologous chromosomes will separate & chromosomes go to opposite side of cell
telophase 1
cytokinesis is completed
nuclear membrane reforms
spindle fibers disappear
end result of meiosis
4 haploid cells that are genetically different
