Unit Two: Cell Structure and Function- essential knowledge

What do ribosomes do

comprise ribosomal RNA (rRNA) and synthesize proteins based on mRNA sequences

Where are ribosomes found and what does this indicate

all forms of life reflecting common ancestry

How does the endoplasmic reticulum (ER) appear and what are its general functions

rough (membrane-bound ribosomes)- compartmentalizes cell

smooth- detoxification and lipid synthesis

How does the Golgi complex appear and what is its general function

flattened membrane sacs- folding of polypeptide chains and protein trafficking

What is the structure of mitochondria

double membraned (outer smooth, inner convoluted with folds)

What are lysosomes

membrane-enclosed sacs with hydrolytic enzymes

What are vacuole

membrane-bound sac with varying roles

What is the structure of chloroplasts and their functions

double outer membrane, used for photosynthesis processes

What does the endoplasmic reticulum do

provide mechanical support, carries out protein synthesis on, and intracellular transport

What does the mitochondrial double membrane do

provides compartments for different metabolic reactions

What do lysosomes do

with hydrolytic enzymes; intracellular digestion, recycling of organic matter, and apoptosis

What do vacuoles do

storage and release of macromolecules and cellular waste, water retention

Why does the inner cellular membrane fold

increases surface area allows more ATP synthesized

How are the thylakoids organized

into stacks called grana

What within chloroplast allows for energy usage

thylakoids and stroma

Where and what is the stroma

fluid within the inner chloroplast membrane and outside the thylakoid

Where does the Calvin-Benson cycle occur and what does it do

occurs in the stroma for photosynthesis

Where does the Kerbs Cycle occur and what does it do?

occurs in the matrix of the mitochondria for the citric acid cycle

Where does electron transport and ATP synthesis occur

occurs in the inner mitochondrial membrane

What do surface area-to-volume ratios affect

ability of biological systems to obtain necessary resources, eliminate waste products, acquire or dissipate thermal energy, and exchange chemicals and energy with the environment

Equation for the volume of a sphere

Equation for the volume of a cube

Equation for the volume of a rectangular solid

Equation for the volume of a cylinder

Equation for the surface area of a sphere

Equation for the surface area of a cube

Equation for the surface area of a rectangular solid

Equations for the surface area of a cylinder

What is true about smaller cells

surface area-to-volume ratio is high with effective exchange of materials with the environment

What happens with volume increases

surface area decreases, demand for internal resources increases, and environment-cell exchange decreases

What is necessary for cell structures to exchange materials

complex structures (i.e membrane folds)

What two regions does a phospholipid have and what are their orientation

hydrophilic- toward aqueous external/internal environment

hydrophobic- toward each other within inner membrane

What can proteins be

hydrophilic- charged, polar side groups

hydrophobic- non-polar side groups

What do cell membranes contain

phospholipids, proteins, steroids, glycoproteins, glycolpids

What does the cell membrane structure result in as described by what model

selective permeability, fluid mosaic model

What do cell membranes do

separate internal and external environments

What can pass through the membrane freely

N2, O2, and CO2

What can pass through the membrane with embedded channels and transport proteins

hydrophilic substances, large polar molecules, and ions

How does H2O pass through the membrane

in small amounts

What do cell walls provided

structural boundaries and permeability barrier

What are cell walls composed of

complex carbohdrates

What does active transport require and what does it does passive transport do

import of materials and waste export

What does active transport require and what does it do

direct energy input for the movement of molecules from low concentration to high concentrations

What does selective permeability allow for

formation of concentration gradients of solutes across the membrane

What do the endocytosis and exocytosis process require

energy

What is the exocytosis process

internal vesicles fuse with the plasma membrane and secrete large macromolecule out of the cell

What is the endocytosis process

cell takes in macromolecules and particulate matter by forming new vesicles

Where does large water quantities pass through

aquaporins

Where do charged ions (i.e Na+ and K+) pass through

through membrane with channel proteins

How does water move

with osmosis from areas of high water potential/low osmolarity/low solute to areas of low water potential/high osmolarity/high solute

Equation for the water potential

how is growth and homeostasis maintained

constant movement of molecules across membranes

What does osmoregulation do

maintain water balance and allow organisms to control their internal solute composition/water potential

Equation for the solute potential of a solutions

What do membranes and membrane-bound organelles do in eukaryotic cells

compartmentalize intracellular metabolic processes and specific enzymatic reactions

How do internal membranes facilitate cellular processes

minimizing competing interactions and increasing surface area in reaction areas

Where did membrane-bound organelles evolve from

free-living prokaryotic cells via endosymbiosis