Biology: Cell Transport Knowt for my little brother, Rohaan

study this rohaan so you can pass your bio test this week

Cell Theory

1. All living things are made of cells. 2. Cells are the basic unit of life. 3. All cells are produced by other living cells.

Prokaryotes

Do not have a nucleus, single-celled organisms. Ex. bacteria.

Eukaryotes

Have a nucleus to contain the genetic material and membrane-bound organelles; bigger! Ex. fungi, one-celled and multicellular organisms, including plants and animals.

Surface Area to Volume Ratio

Eukaryotic cells face a surface area to volume (SA:V) challenge because their larger size results in a lower SA:V ratio.

Cytoskeleton

Network of protein fibers that supports the cell (simpler structure in prokaryotes).

Microtubules

Wide fibers that form centrioles; also direct movement in the cilia or flagella; form tracks for a transport system; composed of the protein tubulin which forms a hollow tube.

Intermediate Filaments

Support the cell, cage around nucleus and support other organelles.

Microfilaments

Formed by protein actin, small filaments that allow for contraction.

Cytoplasm

Refers to everything outside of the nucleus, includes cytosol, and materials and organelles in it.

Nucleus

In eukaryotes, contains genetic material (DNA).

Nuclear Envelope

A double membrane that has nuclear pores = channels that allow information containing molecules (RNA) out of the nucleus.

Nucleolus

Darkest part of nucleus, lots of transcription activity copying message of the DNA.

Ribosomes

Make proteins; have a small and large subunit; read RNA transcript of DNA genetic code and join appropriate amino acids into sequence; located outside the nucleus AND on Endoplasmic Reticulum.

Transcript

The same message in a different format; DNA message is transcribed into mRNA (messenger RNA).

Endoplasmic Reticulum

System of membranous tubules that transports materials throughout the cell.

Rough ER

Has ribosomes attached to the membrane that synthesize proteins directly into the ER.

Smooth ER

Does not have ribosomes attached.

Levels of Organization

In multicellular organisms: organelles < cells < tissues < organs < organ system < organism.

Mitochondria

the powerhouse of the cell

ATP

Adenosine Triphosphate, the energy currency of the cell

Cellular respiration

the series of chemical reactions that convert energy from glucose into ATP

Vesicle

membrane bound transport organelle

Vacuole

vesicle for storage (of water or other materials)

Secretory vesicles

transport materials out of the cell by fusing with the cell membrane

Transport vesicles

vesicles that transport materials from one place in a cell to another

Amylase

breaks down starches into sugars

Protease

breaks down proteins into amino acids

Nuclease

breaks down nucleic acids into nucleotides

Lipase

breaks down fats into fatty acids

Chloroplast

solar power plant, contains chlorophyll

Thylakoids

sacs organized in stacks called grana, contain chlorophyll

Stroma

fluid in the chloroplast

Photosynthesis

occurs in the chloroplast, where light energy is converted into C-C bonds of glucose

Cell Wall

exterior network of molecules that protect the cell and give it strength and support

Cell Membrane

composed of phospholipids

Phosphate head

hydrophilic (water loving) part of a phospholipid

Carbon chain tails

hydrophobic (water fearing) part of a phospholipid

Fluid Mosaic Model

model describing the structure of cell membranes with proteins, lipids, and carbohydrates

Homeostasis

steady state of equilibrium, referring to conditions and materials needed for life

Simple diffusion

the movement of substances from areas of high concentration to low concentration

Passive Transport

Movement of molecules across a membrane with no input of energy.

Facilitated Diffusion

Movement of substances down a concentration gradient with assistance of a channel.

Osmosis

Movement of water across a membrane to an area of high solute concentration.

Solution

Homogeneous mixture in which every particle of solute is fully surrounded by the solvent.

Solute

Substance dissolved (lesser amount).

Solvent

Substance doing the dissolving (greater amount).

Hypertonic Solution

Has a solute concentration HIGHER than inside cell.

Hypotonic Solution

Has a solute concentration LOWER than inside cell.

Isotonic Solution

Has a solute concentration SAME as inside cell.

Active Transport

Transport that requires an input of energy.

Primary Active Transport

Pumps that use ATP to pump substances against the concentration gradient.

Secondary Active Transport

Uses a difference in charge to power movement of substance against the concentration gradient.

Exocytosis

Vesicle merges with cell membrane to expel material.

Endocytosis

Vesicle forms by infolding of membrane to bring material in.

Phagocytosis

Engulfing of smaller cell.

Pinocytosis

Bringing in fluid.

Sodium-Potassium Pump

Pumps three sodium and two potassium ions against their concentration gradient using ATP.

Sodium Dependent Glucose Cotransporters

Symport proteins that allow sodium to flow down concentration gradient and take glucose with it, pushing glucose UP its concentration gradient.

Diffusion

Movement of substances from an area of high concentration to low concentration.

Effect of Hypertonic Solution on Cell

Cell loses water.

Effect of Hypotonic Solution on Cell

Water moves INTO cell in an attempt to reach equilibrium; can burst cell.

Effect of Isotonic Solution on Cell

Zero net movement of water.

Difference Between Active and Passive Transport

Active transport requires the addition of energy.

Example of Primary Active Transport

Na/K pump.

Potassium Ions Moved in Na/K Pump

2 potassium ions are moved for every 3 sodium ions.