biology senior exit exam

4 main macromolecules

carbohydrates, lipids, proteins, nucleic acids

monomers

building blocks of macromolecules or polymers

___ are the monomers of carbohydrates

monosaccharides

___ are the monomers of proteins

amino acids

___ are the monomers of lipids

fatty acids

___ are the monomers of DNA

nucleotides

1st law of thermodynamics

energy can't be created or destroyed, only converted

second law of thermodynamics

every energy transfer or transformation increases the entropy of the universe

entropy

measure of disorder or randomness of a system

enzyme

protein that acts as a biological catalyst and speeds up a chemical reaction

3 ATP producing pathways

glycolysis, citric acid cycle/oxidative phosphorylation, and beta oxidation

glycolysis

the breakdown of glucose/sugar by enzymes in anaerobic conditions, releasing energy and pyruvic acid

ATP

adenosine triphosphate, main source of energy for cells

glucose

C6H12O6

how is energy released from ATP

a phosphate is removed

hydrolysis

the chemical breakdown of a compound due to reaction with water

fermentation

cells release energy in the absence of oxygen, makes alcohol and lactic 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 in mitochondria

electron transport chain

series of electron carrier proteins that shuttle high-energy electrons during ATP-generating reactions

ATP synthase

enzyme that catalyzes the reaction that adds a high-energy phosphate group to ADP to form ATP

where does photosynthesis occur

chloroplasts in plant cells

where does cellular respiration occur

mitochondria and cytoplasm

transcription

DNA is converted to RNA

translation

mRNA decoded to assemble polypeptides and a protein is produced

four types of post translational modification

phosphorylation, acetylation, hydroxylation, and methylation

phosphorylation

the addition of a phosphate group to a molecule

acetylation

addition of acetyl group

hydroxylation

addition of a hydroxyl group

methylation

addition of a methyl group

proteolysis

breakdown proteins

3 sites of major protein sorting

golgi complex, plasma membrane, and endosomes

endosome

Vesicle formed when a cell takes up material from the surrounding environment using the process of endocytosis

where are transmembrane proteins inserted

endoplasmic reticulum membrane

transmembrane proteins

span the membrane

cotranslational sorting

the sorting process in which the synthesis of certain eukaryotic proteins begins in the cytosol and then halts temporarily until the ribosome has become bound to the ER membrane

four types of chemical signaling found in cells

paracrine signaling, autocrine signaling, endocrine signaling, and signaling by direct contact

paracrine signaling

signal released from a cell has an effect on neighboring cells

autocrine signaling

cells respond to signaling substances that they themselves secrete (target themselves)

endocrine signaling

secreted molecules diffuse into the bloodstream and trigger responses in target cells anywhere in the body

signaling by direct contact

cell targets a neighboring cell through a gap junction

gap junction

channel between two adjacent cells that allows substances to pass between cells, enabling the cells to communicate

cell

smallest unit of life

3 things all cells have in common

cell membrane, cytoplasm, DNA

eukaryotic cells

have a nucleus and other membrane-bound organelles, more complex

prokaryotic cells

do not have a nucleus or other membrane-bound organelles, unicellular and often bacteria

organelle

specialized structure that performs important cellular functions within a eukaryotic cell

nucleus

control center of the cell that contains genetic material

chromatin

form of DNA found inside nuclear membrane

chromosomes

threadlike structures made of DNA molecules that contain the genes

nucleolus

produces ribosomes

ribosomes

protein synthesis

cytoplasm

jellylike fluid inside the cell in which the organelles are suspended

endoplasmic reticulum

smooth or rough depending on presence of ribosomes, packages

vesicle

small cavity or sac that contains materials in a eukaryotic cell

golgi apparatus

stack of membranes in the cell that modifies, sorts, and packages proteins from the endoplasmic reticulum

vacuoles

stores food, water, wastes, and other materials

lysosomes

cell organelle filled with enzymes needed to break down certain materials in the cell

mitochondria

powerhouse of the cell, produces energy (ATP) for cell

t/f cells that need more energy have more mitochondria

true

cytoskeleton

network of protein filaments within some cells that helps the cell maintain its shape and is involved in many forms of cell movement

microfilaments

Fine, threadlike proteins found in the cell's cytoskeleton

microtubules

hollow rod composed of tubulin proteins that makes up part of the cytoskeleton in all eukaryotic cells and is found in cilia and flagella

autotrophic

organisms that make their own food by using energy to convert inorganic molecules into sugars, likely undergo photosynthesis

chloroplast

organelle found in cells of plants and some other organisms that captures the energy from sunlight and converts it into chemical energy (photosynthesis)

chlorophyll

green pigment in plants that absorbs light energy used to carry out photosynthesis

cell wall

rigid structure that surrounds the cell membrane and provides support to the cell (ONLY found in plants)

cell membrane

thin, flexible barrier around a cell; regulates what enters and leaves the cell

difference between plant and animal cells

plant cells have chloroplasts and cell walls, while animal cells do not

cilia

hairlike projections on the outside of cells that move in a wavelike manner

flagella

long, whip-like filament that helps in cell motility

the only human cell with a flagellum is ___

sperm

selectively permeable membrane

a property of cell membranes that allows some substances to pass through, while others cannot

phospholipids

A molecule that is a constituent of the inner bilayer of biological membranes, having a polar, hydrophilic head and a nonpolar, hydrophobic tail

hydrophilic

water loving

hydrophobic

water hating

phospholipid bilayer

plasma membrane layers composed of phospholipid molecules arranged with polar heads facing the outside and nonpolar tails facing the inside

cholesterol

lipid that forms an essential component of cell membranes

role of proteins in membrane

structural support, transports/channels, receptors, self markers

extracellular space

space outside the cell

cell theory

fundamental concept of biology that states that all living things are composed of cells; that cells are the basic units of structure and function in living things; and that new cells are produced from existing cells

germ theory

the theory that infectious diseases are caused by certain microorganisms known as pathogens or "germs"

3 domains

Bacteria, Archaea, Eukarya

how are bacteria and archae different

archae live in extreme environments while bacteria is everywhere; archae lacks peptidoglycan but some bacteria have it and others don't

where would you find archaea

extreme conditions like hot springs

eubacteria

kingdom of unicellular prokaryotes whose cell walls are made up of peptidoglycan

t/f archae are found to cause NO disease in humans

true

two phases of cell cycle

interphase and mitotic phase

interphase

period of the cell cycle between divisions, cell growth

G1 phase of interphase

cell grows: increase in size and synthesize new proteins and organelles

S phase of interphase

DNA replication

G2 phase of interphase

cell growth, prepares for mitosis checks in division

mitotic phases

prophase, metaphase, anaphase, telophase

cytokinesis

division of the cytoplasm

prophase

chromatin condenses into chromosomes

metaphase

second phase of mitosis, during which the chromosomes line up across the center of the cell

anaphase

the third phase of mitosis, during which the sister chromatids separate and move toward opposite poles

sister chromatids

replicated forms of a chromosome joined together by the centromere and eventually separated during mitosis or meiosis II

telophase

the final phase, in which the chromatids or chromosomes move to opposite ends of the cell and two nuclei are formed along with a nuclear membrane

3 checkpoints in cell cycle

G1, G2, M

DNA replication

the process of making a copy of DNA