Bio Exam 2025

Biomolecule

Any molecule that is produced by a living organism; examples are carbohydrates. proteins, lipids, and nucleic acids.

Carbohydrate

Biomolecules utilized as a primary energy source for living things, such as sugars and starches

Lipid

Biomolecule used to store energy and provide insulation; also, important in cell membrane structure

Amino acids

monomer of building blocks of a polypeptide (protein)

Nucleic acids

an organic compound, either RNA or DNA, whose molecules are made up of one or two chains of nucleotides and carry genetic information

nucleotide

monomer of nucleic acids made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base

enzyme

protein that acts as a biological catalyst; it speeds up chemical reactions by lowering the activation energy

activation energy

energy needed to get a chemical reaction started

substrate

reactant in a chemical reaction using an enzyme

Active site

the region of an enzyme where substrate molecules bind and undergo a chemical reaction

protein

nitrogen-containing macromolecule (composed of amino acids) that performs multiple functions such as hemoglobin, insulin, and enzymes

denaturation

a process in which a protein unravels, losing its specific structure and hence function; can be caused by changes in pH or by high temperature

UNIT 2

CELLS AND VIRUSES

Lysogenic cycle

a viral reproductive cycle in which the viral DNA is added to the host cell’s DNA and is copied along with the host cell’s DNA

lytic cycle

a viral reproductive cycle in which copies of a virus are made within a hot cell, which then burst open, releasing new viruses

eularyote

a cell that contains a nucleus and membrane bound organelles

prokaryote

a unicellular organism that lacks a nucleus and membrane bound organelles

ribosome

a cell structure, consisting of RNA and protein, where translations take place

rough endoplasmic reticulum

transport system of the cell; tubules and sacs leading from the nuclear membrane and connecting to all parts of the cell; contains numerous ribosomes on the surface

smooth endoplasmic reticulum

produces lipids, involved in carbohydrate metabolism, detoxification of drugs and poisons. without ribosomes

Golgi apparatus

stacked membranes that receive, store, package, and secrete proteins transported in vesicles

lysosome

small, round structure that contain enzymes used in digestion

plasma (cell) membrane

a selectively permeable surface that encloses the cell contents and through which all materials entering or leaving a cell must pass

vacuole

organelle that stores materials such as water, salt, proteins, and carbohydrates

flagella

whiplike tails to aid in movement

cilia

hairlike projections that are used for movement

capsid

outer protein coat of a virus

cell

smallest unit of life

envelope

a membrane like layer that covers the capsids of some viruses

UNIT 3

CELLULAR ENERGY

ATP

main energy source that cells use for most of their work

cellular respiration

process that reales energy by breaking down glucose and other food molecule

cholorplast

organelle that carries out photosynthesis

mitochondria

organelle that is the site of ATP (energy) production through aerobic respiration

photosynthesis

conversion of light energy from the sun into chemical energy stored in glucose

UNIT 4

CELL CYCLE

meiosis

a type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes

interphase

stage that is in between cell division

mitosis

process of nuclear division that, along with cytokinesis, produces two genetically identical daughter cells

apoptosis

programmed cell death

G1 phase

the first gap, or growth phase, of the cell cycle, consisting of the portion of interphase in which the cell grows and performs its normal functions

S phase

synthesis phase of the cell cycle during which DNA is replicated

G2 phase

second gap, or growth phase, of the cell cycle after DNA synthesis occurs

M phase

phase of the cell cycle that includes mitosis and cytokinesis

DNA replication

process in which DNA makes a duplicate copy of itself prior to cell division

UNIT 5

GENETICS

allele

alternative form that a single gene may have for a particular trait

codominance

a condition in which both alleles for a gene are fully expressed

crossing over

exchange of genetic material between a pair of homologous chromosomes durong prophase I of meiosis