Biology Clep Modern States Molecular and cellular biology

Everything modern states covers for the clep test in a knowit

Cell Cycle

ordered series of events involving cell growth and cell division that produces two new daughter cells

What stage does a cell spend 90% of it’s life in

interphase

What stage does a cell spend 10% of it’s life in

miotic phase

What is the miotic phase

Phase where cell division happs the DNA and cytoplasmic contents are seperated and the cell divides.

What happens in the G1 phase

Cell growth, organelle replication, metabolic preperation (accumulating energy reserves and molecular building blocks (nucleotides and amino acids) needed to replicate DNA), enzyme production

what happens in the S phase

DNA synthesis, cell duplicates dna, centrosome duplicates, the cell also goes through a checkpoint to make sure there is no error before proceding

What happens in the G2 phase

cell growth, DNA Repair and Checking, Protein and Tubulin Synthesis, Organelle Duplicationd

What happens in the g3 phase

cell division/mitosis

Interphase is when

the cell undergoes normal growth processes while also preparing for cell division

First stage of mitosis

karyokinesis/mitosis

second stage of mitosis

cytokinesis

Order of mitosis

PMAT

Prophase

The chromatin condenses into visible, X-shaped chromosomes. The nuclear envelope begins to break down, and structures called centrioles move to opposite ends of the cell to begin building the mitotic spindle

Metaphase

: The nuclear membrane dissolves entirely, allowing the spindle fibers to attach to the center (centromere) of each chromosome. The spindle fibers then push and pull the chromosomes until they are perfectly aligned in a single file line along the middle of the cell

Anaphase

The spindle fibers rapidly shorten, pulling the sister chromatids (the two identical halves of the X-shaped chromosome) apart. These newly separated chromatids (now considered individual chromosomes) are dragged to opposite ends of the cell.

Telophase

The chromosomes reach the opposite poles and begin to de-condense back into long, thin strands. A new nuclear envelope forms around each of the two separated sets of DNA, effectively creating two identical nuclei within the single cell

Cytokinesis

cleavage furrow (crack) forms in the middle of the cell and the cells split into two

Animal cells split with a

cleavage furrow

Plant cells split with a

cell plate

G0 Phase

cell stage where the cells are not actively preparing to divdie

what happens during the G1 Checkpoint happens before S phase

check for genomic DNA damage, cell commits to the division process, checks for adequate reserves and cell size.

what happens during the G2 Checkpoint before miotic phase

cell size and protein reserves are assesed, ensuring that all chromosomes have been replicated and the DNA is not damaged. If cell does not pass this checkpoint the cell cycle is halted and DNA replication completion or repair is started.

M checkpoint

spindle checkpoint. ensures that the spindle fibers are correctly attached to the microtubules.

cyclins

one of a group of proteins that act in conjunction with cyclin-dependent kinases to help regulate the cell cycle by phosphorylating key proteins; the concentrations of cyclins fluctuate throughout the cell cycle

cyclin-dependent kinases

one of a group of protein kinases that helps to regulate the cell cycle when bound to cyclin; it functions to phosphorylate other proteins that are either activated or inactivated by phosphorylation

diploid

cell, nucleus, or organism containing two sets of chromosomes (2n)

gamete

haploid reproductive cell or sex cell

homologous chromosomes

chromosomes of the same morphology with genes in the same location; diploid organisms have pairs of homologous chromosomes (homologs), with each homolog derived from a different parent. They match but they are not identical

oncogene

mutated version of a normal gene involved in the positive regulation of the cell cycle

p21

cell cycle regulatory protein that inhibits the cell cycle; its levels are controlled by p53

p53

cell cycle regulatory protein that regulates cell growth and monitors DNA damage; it halts the progression of the cell cycle in cases of DNA damage and may induce apoptosis

Cancer

result of unchecked cell division. Loss of control begins with a change in DNA sequence of a gene that codes one of the regulatory molecules, leading to a protein not functioning correctly. One distruption leads to other mistakes. Every cell division after that will lead to daughter cells with mroe and more damage, eventually leading to rapidly reproducing cells causing a tumor.

What is not necessary in bacterial cell division

mitosis because bacteria lack a nucleus and only have a single, circular chromosome. They divide instead through binary fission.

Which of the following occurs only during meiosis, not mitosis?

Crossing over between homologous chromosomes

Haploid cells contain

one set of chromosomes

meiosis

a nuclear division process that results in four haploid cells/ the production of gametes

Meiosis 1 and meosis 2 phases

Pass Me A Taco Cheff

prophase, metaphase, anaphase, telophase, and cytokeniss

Prophase 1

Each chromosome pairs off with its homologous match. the chromosomes also cross over.

Crossing over

when chromosomes swap sections of DNA by exchanging alleles

Metaphase 1

when the spindle fibers reach out to the chromosomes and pull them into a row in the center

Anaphase 1

spindles tug the chromosome pairs apart

Telophase 1

membrane seals each group into a seperate nucleous

Cytokenisis 1

groups pinch off into two seperate cells with only half of the genetic material that they had orginally.

Prophase 2

the chromosomes clump together

Metaphase 2

spindle fibers reach out and line up the cells in trhe center

Anaphase 2

cells are split in half and the halves are mvoed to opposite ends of the cells

Telophase 2

membrane appears in both cells

Cytokenisis 2

cell pinches off into 4 different hapoloid cells

nondisjunction

the failure of paired chromosomes or sister chromatids to separate properly during cell division. This error results in daughter cells with an abnormal number of chromosomes

histones

proteins that dna winds itself around

centromere does what

holds sister chromatids together

ploidy

number ofcopies of genes or choromosomes abreviates as a number followed by the letter n

karyotope

picture of chromosomes

matter

anything that takes up space and has mass, mad of elements

elements

cannot be broken down to other substances

atom

smallest unit of matter w/ elements properties

compound

2 or more elements combined in fixed ratio

molecule

2 or more elements combined in fixed ratio

four elements common to all living organisims

oxygen (O), carbon (C), hydrogen (H), and nitrogen (N)

atomas are most reactive if the valence shell is ____

incomplete

chemical bonds

attractions that keep atoms close together

covalent bonds

sharing of a pair of electrons, strong bonds

nonpolar bonds

sharing is equal

polar bonds

sharing is unequal and it creates partial charges (poles)

Ionic bonds

one atom (anion) steals electron, other atom (cation) loses electron, strong bonds

Cation

positively charged ions formed when an atom loses electrons

anion

negatively charged ions formed when an atom gains electrons

Hydrogen bond

Form between poles of H and O in water molecules, weak bonds

Humas are 65%

oxygen

Humas are 18%

carbon

Humas are 10%

hydrogen

Humas are 3%

nitrogen

1st law of thermodynamics

energy can’t be created or destroyed

2nd law of thermodynamics

reactions tend to increase disorder (make energy less available for cells )

endothermic reactions

take energy

exothermic reactions

release energy

water is a

universal solvent

acids

disolve in water and increase relative H+ (hydrogen) ion concentration in the solution

Bases

disolve in water and decrease the H+ (hydrogen) ion concentration in the solution

pH of 7 or higher

alkaline

pH of 7

neutral

pH of 7 or lower

acidic

any molecule containing carbon is called ____

organic

Monomers

small, basic molecules that act as the building blocks of larger molecules

Polymers

large, complex chains made by bonding many of these smaller monomer units together

Carbohydrates

made only of carbon, oxygen, and hydrogen

Carbohydrates monomer name

monosaccharide ex: glucose

Carbohydrates polymer name

polysaccharde ex: starch

Lipids

molecules goup together b/c of hydrophobic properties

Common lipids

waxes, fats, phospholipids, steroids

What are waxes?

form water barriers

fats are for?

energy storage

phospholipids are for?

cell membrances

steroids are?

hormones

Proteins functions

enzymes

defense - antibodies

muscle - fibers

Protein monomer name

amino acids

Protein Polymer name

polypeptide (prodtein)

What does a peptide bond do?

holds amino acids together

Nucleic acids function

information storge ex: DNA/RNA

What are the two types of nucleic acids?

deoxyribonucleic acid and ribonucleic acid