Cell Test

3 parts of cell theory

1. All organisms are composed of 1 or more cells

2. The cell is the basic unit of structure of organization in organisms

3. All cells come from preexisting cells

Golgi Apparatus

receives, modifies & sorts proteins for transport (made up of flat vesicles that package things to be transported around or leave the cell)

Ribosomes

little grains floating around inside the cell where proteins are synthesized

In all cells (pro&eukaryotes)

Endoplasmic Reticulum

Series of membranes involved in protein synthesis

• ER works with ribosomes to produce proteins for secretion (series of folded membrane pathways spotted by ribosomes)

• Smooth ER stores CA++ & detoxifies

Chloroplasts

membrane bound organelle found in plants & algae

• uses sun’s energy to convert CO2 to glucose (photosynthesis)

Cell (plasma) Membrane

A selectively permeable/semipermeable membrane that determines what gets into/out of the cell

(boundary between internal & external)

Cilia & Flagella

Flagella: Single tail

Cillia: many tails (looks hairy)

Hairlike projections used for cell movement through liquid or moving the liquid itself around

Lysosomes

Membrane-bound packets of hydrolytic enzymes (vesicles with digestive enzymes) that break down waste, foreign invaders, old cell parts etc.

Nucleus

Contains the DNA (DNA codes for proteins) & all our genetic info

Cell Wall

provides structural support to plant cells (& fungi)

Mitochondria

have double membrane that folds in on itself forming little finger-like projections called cristae, break down sugars into ATP through chemical conversion which is used as cell energy

Solution

A liquid with one or more substances dissolved in it

Solvent

liquid that the solute is dissolved in

Solute

Substance dissolved in a solution

Concentration

how strong it is→the solute/volume (percentage)

• more particles=higher concentration

For cell to survive

concentration solutes

Concentration gradient

Occurs when there is a difference in concentrations

Diffusion

particles move high→low concentration to reach an equal concentration (equilibrium on each side)

Passive Transport

Molecules move high→low (no energy)

with/along/down concentration gradient

Active Transport

Molecules low→high (with energy)

against/up concentration gradient

Equilibrium=no movement?

• No, molecules are constantly moving but net movement=zero

Which direction do particles move in?

• molecules move randomly but net movement high→low

1 Type of Transport: Simple diffusion

Transport protein used?

• No

Direction of Movement?

• with concentration gradient (high→low)

Requires energy input from cell?

• No

Types of substances?

• CO2, O2 (small molecules)

Classification of transport?

• Passive

2 Type of Transport: Facilitated Diffusion

Transport protein used?

• Yes: channel proteins/carrier proteins

Direction of movement?

• With concentration gradient

Requires energy input from cell?

• No

Types of substances?

• Glucose, water, (large polar) or ions (NA+)

Classification of Transport?

• Passive

3 Type of Transport: Active Transport

Transport proteins used?

• Yes: Pumps

Direction of Movement?

• Against concentration gradient (low→high)

Requires energy input from cell?

• Yes (ATP)

Types of Substances?

• NA+ ions & K+ ions

Classification of transport

• Active

Endocytosis

Process of taking material into the cell by folding in pockets of the cell membrane into pouches called vesicles by forming a vacuole around it

Phagocytosis

endocytosis involving large solid particles

Pinocytosis

endocytosis involving liquid

Exocytosis

the process of removing material out of the cell where vesicles merge with the cell membrane to release contents, expelling waste from a vacuole

Osmosis

The diffusion of water

• through aquaporin proteins

• with concentration gradient (high→low) of water

• no additional cell energy required

• passive transport

Water vs. Salt

Water goes towards salt (salt sucks)

Concentration strength: isotonic

the solution & the cell have the same solute concentration strength-no osmosis

Concentration strength: Hypotonic

the solution with lower solute concentration (out→in)-causes osmosis

Concentration strength: hypertonic

the solution with the higher solute concentration (salt=solute) (in→out)-causes osmosis

Homeostasis (water balance)

maintaining internal environment water & solute concentrations

Excretory system

accomplishes both water balance & waste removal (several organs are important in removing waste from the body)

• Liver: converts excess protein into urea→ Kidneys: remove unwanted substances such as urea, excess water & salt

Urea

Excess amino acids in body are broken down by liver→ammonia→urea

• process is important because it converts toxic ammonia→urea (less toxic)

• Once formed urea is transported by the circulatory system to the kidneys

• The kidneys filter the blood, removing urea & excess water & salt, which forms urine

• Urine is stored in the bladder before being excreted from the body

Path of Nitrogenous Waste

Cells break down proteins→Ammonia→Liver→Urea→Kidneys→Urine

Nuclear membrane

Membrane surrounding the nucleus that determines what goes in and out of it

Cytoplasm

watery medium in which all organelles float

vacuoles

large membranous sacks for storing things

Channel protein

Transport protein that provides a tube-like opening in the plasma membrane through which particles can diffuse

Carrier protein

transport protein that changes shape when a particle binds it (sodium & potassium ions)

Nephron

Functional unit of the kidney (millions)

• concentrate/remove waste from the blood & reclaim liquid + important nutrients

Purpose of kidney

• keep what’s beneficial

• eliminate waste (urea)

• balance water

Filtration 1st stage Kidney nephron

blood cells, platelets, other large components stay in blood vessels

Filtrate (stuff first collected): water, urea, uric acid, glucose, amino acids, salts etc. are forced into Bowman’s capsule (glomenular capsule)

cells stay in blood, liquid plasma w/dissolved solutes goes into glomerulus

Reabsorption 2nd stage Kidney

Reabsorption from the liquid filtrate to the blood can occur by passive or active transport

• Filtrate descends down from the loop of Henie (loop of the nephron) & as it moves, important molecules & ions are reabsorbed into the blood

Active Secretion step 3 Kidney

Some substance are moved by active transport from the blood into the loop of the nephron to the eventual urine

How is osmoregulation achieved?

Filtrate moves through the nephron down the loop, water moves by osmosis from the nephron to the fluid & is taken up by the cappilaries)

• outerpart less salty-kidneys

• innter part very salty (hypertonic)-kidneys

As traveling down the kidney, solution becomes more concentrated, kidney also becomes more concentrated to utilize osmosis

salt gradient purpose: to pull/reclaim the water (produced by active transport & passive transport)

Water is pulled out of the filtrate & reclaimed by osmosis

Lower abdominal area

Phospholipid bilayer

two layered arrangement of phospholipid molecules forming cell membrane

Phospholipid’s composed of hydrophilic head & two hydrophobic fatty acid tails

Aquaporin

Several proteins found in cell membrane that selectively permit water to pass in and out of the cell

Glycoproteins

identify cells as familiar or foreign, help cells bind