BIO 103- Exam 2 Flashcards
metabolism
chemical reactions in a cell, building and breaking down of complex molecules, reactions consume or generate energy
anabolic reaction
smaller molecules are built into large ones, energy is required (photosynthesis)
catabolic reaction
large molecules are broken down into smaller ones, results in energy (respiration)
enzymes
involved in metabolic reactions, speed up biochemical reactions, Makes the bond-breaking and bond-forming processes easier
how do enzymes work?
-the substrate binds to the active site of the enzyme
-the enzyme and substrate form a substrate complex
-the products are released and the enzyme starts again
competitive inhibition
inhibiting molecule has a structure similar to the substrate, competes with the substrate for the active site, Inhibitor binds to the active site of enzyme, reaction does not occur
noncompetitive inhibition
inhibiting molecule binds to enzyme at other location, changes shape of enzyme, the shape of active site is changed, reactants cannot bind to enzyme; reaction does not occur
cellular respiration
Process that releases energy by breaking down glucose and other food molecules in the presence of oxygen, catabolic reaction
ATP
(adenosine triphosphate) main energy source that cells use for most of their work,
aerobic respiration
requires oxygen
glycolysis, citric acid cycle, Oxidative phosphorylation
glycosis
occurs in the cytoplasm, glucose is broken down into pyruvate
citric acid cycle
a series of chemical reactions in the mitochondria, Production of NADH and FADH2
oxidative phospholaytion
NADH and FADH2 broken down to generate more ATP
anaerobic respiration
Respiration that does not require oxygen, glycolysis breaks glucose down into pyruvate and ATP. Pyruvate undergoes fermentation
lactic acid fermentation
Lactic acid produced as a by-product, ex: milk converted to yogurt/cheese, breakdown of glucose in red blood cells of muscles in absence of O2
alcohol fermentation
Ethanol is produced as a by-product, ex: brewing bee, breakdown of glucose by yeast
autotroph
an organism that makes its own food, uses energy to convert inorganic C to glucose
photoautotrophs
use light as energy source (plants, algae, cyanobacteria)
chemosynthetic autotroph
use chemicals to make food (organisms in hot springs or bottom of the ocean)
hetertrophs
obtain organic carbon and nutrients by consuming other organisms
pigments and light absorption
Visible light is a portion of the electromagnetic radiation (solar energy), absorbed light is used for biochemical reactions, unused light is reflected back
chloroplast
stroma fills the space in chloroplasts and contains dissolved enzymes, starch granules, and chloroplast DNA
thylakoids are discs in chloroplast that contain chlorophyll
photosynthesis
- light reaction: occurs in the thylakoid membrane
- calvin cycle: occurs in the stroma
- 3-C molecule converted to glucose: in stroma
light reaction, photosynthesis
light absorbed by chlorophyll molecule, water broken down to H and 02 (oxygen released), electrons are passed on, NADPH is produced and ATP is generated.
calvin cycle
occurs in stroma of chloroplast, input: CO2, ATP, and NADPH from light cycle, CO2 is converted into a 3-C molecule
3-c molecule
leaves the Calvin cycle and is converted to glucose in stroma of chloroplast
central dogma
DNA -> RNA -> Protein
similarities between DNA and RNA
Both are nucleic acids; both have A, C, and G nucleotides
differences between DNA and RNA
DNA has deoxyribose, thymine, and is double-stranded. RNA has ribose, uracil, and is single-stranded
genotype
genetic make-up of an individual
phenotype
measurable trait of an individual
RNA polymerase
enzyme (protein) that synthesizes RNA molecules, reads information on a sequence of bases in a stretch of DNA
gene expression
process by which a gene produces its product and the product carries out its function
what is a gene?
a gene is a stretch of DNA base pairs that code for a protein (proteins make traits, proteins are also used for other functions)
all genes exist in every cell, but not all genes are expressed in every cell
where is the mRNA made?
nucleus
transcription
RNA polymerase copies the gene from the DNA onto the RNA. The mRNA carries the message from the DNA to the ribosome
codon
sequence of 3 nucleotides, found on the mRNA
anti-codon
group of three bases on a tRNA molecule that are complementary to an mRNA codon
translation
occurs in the cytoplasm, ribosomes read mRNA, tRNA enter the ribosome and carry anticodons to create the protein
what is the end product of translation?
polypeptide chain
why do cells replicate?
cell replication supports carious vital functions such as reproduction, development, growth, and healing
chromosome
a single, long DNA molecule that is wrapped around proteins
replicated chromosome
A chromosome that has been copied; consists of two identical chromatids, each containing one double-helical DNA molecule
locus
position of gene on a chromosome
sister chromatids
Identical copies of a chromosome connected at the centromere
autosomes
chromosomes that are not sex chromosomes
breakdown of human chromosomes
humans have 46 chromosomes, 23 pairs (22 are autosomes, 1 pair of sex chromosomes)
DNA molecule
double-stranded DNA helix
homologous chromosomes
matches pairs of each type of chromosomes, same length, same genes at the same loci
alleles
slightly different versions of a gene
ploidy
number of versions of each type of chromosome or number of sets of chromosomes
the cell cycle
G1, S (synthesis), G2, and M phase
interphase
cell spends most of its time here, consists of G1, S, and G2 phase
mitosis
division of nucleus
cytokinesis
the division of the cell’s cytoplasm
what occurs during the synthesis phase?
DNA replication
cancer and the cell cycle
cancer: uncontrolled cell division, replication errors (mutations) passed on to the daughter cells
meiosis
a type of nuclear division that leads to a halving of chromosome number, production of gametes
asexual reproduction
any mechanism of producing offspring that does not involve the production and fusion of gametes (mitosis)
sexual reproduction
the production of offspring through the production and fusion of gametes, offspring have chromosome combinations unlike those of their siblings or parents
haploid
cells that have one chromosome of each type, number of chromosomes in a haploid cell=n (ex: gametes)
diploid
cells that have two versions of each type of chromosomes, number of chromosomes= 2n, (ex: somatic cells)
meiosis 1
crossing over, reduction in ploidy level, homologous chromosomes separate into different daughter cells, cells are haploid but chromosomes are still replicated
meiosis 2
cells are already haploid, separation of sister chromatids of replicated chromosomes, at the end cells are haploid and unreplicated
homozygous
both alleles are the same version of the gene
heterozygous
the 2 alleles are different versions of the gene
gregor mandel
father of genetics
single trait monohybrid cross
A cross between individuals that differ with respect to a single gene pair
dominant gene
allele that is expressed in homozygous and heterozygous genotype (denoted by capital letter)
recessive gene
allele that is expressed only in homozygous genotype (denoted by a lower case letter)
mendel’s law of segregation
alleles of a gene will segregate into separate daughter cells during meiosis
all life on earth…
are the product of evolution and bear the characteristics common to all living things
three domains of life
bacteria, archaea, and eukaryota
how do we go about determining the relationships of all living organisms
physical traits (anatomy and morphology), molecular data (DNA, DNA, proteins) and ribosomal RNA
bacteria and archea
prokaryotes, unicellular only, asexual reproduction only, some are autotrophs while others are heterotrophs, some are classified as extremophiles
eukarya kingdom
protists, fungi, plants, animals
protists
eukaryote, very diverse, unicellular or multicellular, some groups are photosynthetic autotrophs, others engulf food or absorb nutrition from environment
fungi
can be single-celled (yeast) or multicellular (filaments), are heterotrophs: secrete digestive enzymes into environment then digest and absorb good
types of fungi
saprobes(feed on dead organic matter), symbionts (live in close association with another organism and benefit each other), parasites (feed on living organisms)
animals
multicellular(lack cell wall), move under their own power at some point in their life cycle, have neurons and muscle cell, are heterotrophs (ingest food)
plants
multicellular, cell walls with cellulose, photosynthetic autotrophs
which pathways or processes result in the production of ATP
light cycle of photosynthesis, citric acid cycle, and fermentation
A new plant virus causes the degradation of the stroma of the chloroplast. Which one of the following is likely to be the effect of the viral disease?
Decrease in the rate of synthesis of sugar molecules (Calvin Cycle)
where in the cell does respiration occur?
cytoplasm and mitchondria
What are the possible products and biproducts of anaerobic respiration?
Ethanol, ATP, Carbon Dioxide, Lactic Acid
