AP BIO UNIT 2: Cell Structure and Function

cell

basic unit of life

plasma membrane

The membrane that surrounds the cytoplasm of the cell, separating the inside of the cell from the outside of the cell; selective permeable

cytoplasm

semi-fluid jelly like substance; thee region of the cell outside of the nucleus.

genetic material

carry the genes in the form of DNA

ribosomes

A complex structure of RNA and protein that synthesizes proteins from mRNA; make proteins

Eukaroytes

Describes a cell that has a nucleus; used to refer collectively to animals, plants, fungi, and protists; membrane bound organelles; bound in the nucleus (linear)

Prokaryotes

Describes a cell that does not have a nucleus; used to refer collectively to archaeans and bacteria; circular, smaller, basic

cytoskeleton

network of proteins that are rigid and help the cell keep its shape; also includes flagella and cilia

endosymbiont theory

eukaryotic cells evolved from a symbiotic relationship between different prokaryotic cells, where one cell engulfed another and both benefited; A larger host cell engulfed smaller prokaryotic cells. The host cell provided a safe environment and food, while the engulfed cells provided energy through processes like aerobic respiration or photosynthesis. Over time, this mutually beneficial relationship became permanent, with the smaller cells evolving into organelles within the host cell. Proposes that the mitochondria and chloroplasts in eukaryotic cells originated from free-living prokaryotes that were engulfed by ancestral host cells.  

Mitochondria

Specialized organelles that are the site of cellular respiration in eukaryotic cells, oxidizing chemical compounds such as sugars to carbon dioxide and transferring their chemical energy to ATP. transforms glucose into ATP

Cristae

folds in mitochondria

chloroplasts

contain green pigment called chlorophyll; double membrane with thylakoids inside

plant cells

-have cell walls

-have mitochondria and chloroplasts

-have large central vacuoles

animal cells

-have no cell walls

-do not have chloroplasts

-have centrioles which helps with cell division

nucleus

stores genetic material (DNA)

nucleolus

makes RNA and ribosomes

rough endoplasmic reticulum

makes proteins for export; to synthesize and modify proteins that are destined for secretion from the cell, insertion into cell membranes, or delivery to other organelles like the Golgi apparatus and lysosomes

smooth endoplasmic reticulum

makes lipids and other things; creating lipids for membranes, synthesizing steroid hormones (like testosterone), and detoxifying harmful substances like drugs and poisons

golgi apparatus

processes (folds up) and ships proteins out of cell; a cell organelle that processes, packages, and sorts proteins and lipids for transport within or outside the cel

ribosome

make proteins for the cell

vacuole

A vacuole is a membrane-bound sac within a cell that stores water, nutrients, ions, and waste products; storage center for cell (plants—water)

peroxisome/ lysosome

to act as the cell's "digestive system," breaking down waste materials, cellular debris, and foreign invaders; recycles parts of cell/digests toxins (lots of digestive enzymes) 

cell wall

in plants only; rigidity of plant; made of cellulose (carb)

centriole/centrosome

animal only; helps in cell division

vesicle

small, membrane-bound sacs that transport and store substances within a cell, playing roles in metabolism, digestion, and waste removal. They are used to move materials between organelles, secrete substances like hormones out of the cell, and break down waste products and foreign invaders; part of membrane that can pinch off to transport substances

selective permeability

allows some substances in easier than others; the property of a membrane that allows certain molecules or ions to pass through it by means of active or passive transport, while blocking others.

fluid mosaic model

A model proposing that the phospholipid bilayer is a dynamic structure that allows molecules to move laterally within the membrane and is a mixture, of several components, including lipids, proteins, and carbohydrate; membranes are composed of lipids and proteins (phospholipids being the most prominent) 

cholesterol 

fluidity buffer to keep the membrane fluid at high and low temperatures 

intergral proteins

proteins that are permanently embedded within the cell membrane. They play crucial roles in various cellular functions, such as transport, signal transduction, and maintaining cell structure; transmembrane proteins; penetrate the hydrophobic interior of the membrane

peripheral proteins

A protein that is temporarily associated with the lipid bilayer or with integral membrane proteins through weak non-covalent interactions; not embedded; loosely bound

glycolipids

carbohydrates and lipids

glycoproteins

carbohydrates and proteins

diffusion

movement of molecules so they spread out evenly in the available spaces

osmosis

diffusion of free water across a selectively permeable membrane

tonicity

ability of surrounding solution to gain or lose water

hypertonic solution

more solutes in a solution

hypotonic solution

less solutes in a solution

isotonic solution

equal amount of solutes in a solution and cell

osmotic pressure

pressure applied to a solution to prevent inward flow of water

osmotic potential

the potential of water to move from hypotonic to a hypertonic environment

osmoregulation

cells ability to control solute concentration

flaccid

a plant in an isotonic solution that will not take in water

plasmolyze

when a plant is in a hypertonic solution it will____

channel proteins

located in the membrane, help polar molecules and ions move through the membrane

aquaporins

help move water through cells

ion channels

function as gated channels which open and close depending on the ions

active transport

uses energy to move solutes against their gradient

co-transport

a single ATP molecule can drive the active transport of other solutes

exocytosis

cell secretes a biological molecule

endocytosis

cell takes in a biological molecule

phagocytosis

cell eating

pinocytosis

cell drinking

ligand

any molecule that binds to a receptor on another molecule