cells

Biology

Characteristics of Living Things

Reproduction

Growth

Characteristics of Living ThingsDevelopment

Energy Capture

Characteristics of Living Things

Energy UtilizationResponse to Stimuli

Characteristics of Living Things

Composed of Cells

Adaptation

Basic BiochemistryTextbook Chapter 3 (Sections 1 and 3)

Biochemistry Atom: single unit,

found on periodic table

Molecule: combination of multiple atoms via bonds

Element (atoms) vs. Compound (molecules)

Cells

Levels of Organization “SMALLER” LEVELS

Cells Tissues* Organs Organ Systems Organisms

“LARGER” LEVELS

Organisms Populations* Communities* Ecosystems Biosphere

“Cell” Theory1. All living things are made of cells.

2. Cells are the basic units of structure and function within organisms.

3. All cells are derived from other cells.

Macromolecules

4 Essential Macromolecules All carbon-based

because…

Smaller molecules LINKED to form chains, called “polymers”

Important in nutrition

1.) CARBOHYDRATES Structure: single sugars (carbon rings)

which can be joined

Monosaccharides (1), Disaccharides (2), Polysaccharides (many)

1.) CARBOHYDRATES Primary energy source

(utilized first)

Cell-recognition

Structural support (chitin and cellulose)

Examples in foods: starches, sugars, bread, and fruit

2.) LIPIDS Structure: long carbon/hydrogen chains

Fats, waxes, oils

One use: long-term energy storage

2.) LIPIDS Often insoluble (barrier to water) because

hydrocarbon chains are “hydrophobic”

What things are made out of lipids?

3.) PROTEINS Structure: small AMINO

ACIDS linked into long chains

20 different amino acids

Function of a protein related to order of AAs

3.) PROTEINS Structural building blocks of cells (tissue, bones, skin, muscles)

Extremely complicated structures,

Also called“polypeptides”

4.) NUCLEIC ACIDS DNA carries genetic information

Structure: small “nucleotides” linked together

Order of four different nucleotides creates the “code” found in DNA

ATP: energy currency in cells

Topics Covered: Week 1 Characteristics of living things

(1.4) Cell theory (7.1) Basic chemistry (3.1, 3.2) Levels of organization (7.3) Four macromolecules (3.3)

Water Interactions

Cell Environment Primarily water

Molecules are dissolved / suspended

Types of Solute (Solute = dissolved

particles)

HYDROPHILIC (usually have pos. or neg. charge)

HYDROPHOBIC (usually uncharged)

Cells

Cell Size/Shape Varies based on type of

cell

Ex. Neurons are thin, but can be nearly a meter

Size scale: micrometers (μm)

Why are cells so small? A small volume (size)

requires fewer nutrients

A larger surface area allows a cell to transport more across the cell membrane

Surface Area-To-Volume Ratio Most efficient cells

have small volumes and large surface areas

A large surface area-to-volume ratio is best

Surface Area-To-Volume Ratio The larger the cell, the smaller the SA-V ratio

Diameter of cube:

Surface area:

Volume:

Ratio:

Surface Area-To-Volume Ratio The larger the cell, the smaller the SA-V ratio

Diameter of cube: 1 μm

Surface area: 6 μm2

Volume: 1 μm3

Ratio: 6.0

Surface Area-To-Volume Ratio The larger the cell, the smaller the SA-V ratio

Diameter of cube: 1 μm 2 μm

Surface area: 6 μm2 24 μm2

Volume: 1 μm3 8 μm3

Ratio: 6.0 3.0

Surface Area-To-Volume Ratio The larger the cell, the smaller the SA-V ratio

Diameter of cube: 1 μm 2 μm 3 μm

Surface area: 6 μm2 24 μm2 54 μm2

Volume: 1 μm3 8 μm3 27 μm3

Ratio: 6.0 3.0 2.0

Surface Area-To-Volume Ratio The larger the cell, the smaller the SA-V ratio

Diameter of cube: 1 μm 2 μm 3 μm 4 μm

Surface area: 6 μm2 24 μm2 54 μm2 96 μm2

Volume: 1 μm3 8 μm3 27 μm3 64 μm3

Ratio: 6.0 3.0 2.0 1.5

Surface Area-To-Volume Ratio The larger the cell, the smaller the SA-V ratio

Diameter of cube: 1 μm 2 μm 3 μm 4 μm 5 μm

Surface area: 6 μm2 24 μm2 54 μm2 96 μm2 150 μm2

Volume: 1 μm3 8 μm3 27 μm3 64 μm3 125 μm3

Ratio: 6.0 3.0 2.0 1.5 1.2

Surface Area-To-Volume Ratio By increasing surface area with

folds, cells can be more efficient

PROKARYOTIC CELLS Bacteria

First organisms on Earth

No nucleus. Few cell structures.

EUKARYOTIC CELLS Part of multi-celled

organisms

More specialized

Nucleus and membrane-bound organelles

What Cells Do… All the functions that

allow an organism to survive

Including: respiration, growth, reproduction, energy utilization, etc.

Cell Membrane Outer covering of all

cells Gives cell its shape Controls what enters

and exits the cell Made up of lipids

(hydrophobic)

Nucleus “Brain” of the cell Controls all functions Contains DNA

(chromosomes) Surrounded by a

NUCLEAR MEMBRANE that is similar to the cell membrane

Cytoplasm Watery, jelly-like material that

contains dissolved solutes, nutrients, etc.

Located in-between cell membrane and nucleus

Surrounds most other cell parts

Ribosomes Made of protein & RNA

Structures in which proteins are made

Some proteins kept, others exported by Endoplasmic Reticulum

Mitochondria Small, rod-like

structures “Powerhouse” of the

cell Extract energy from

food and makes ATP

What kind of cells have the most?

Vacuoles Storage sacs

within cells Can store: food,

water, minerals, waste, or toxins

MUCH larger within plant cells (keeps plant rigid)

Lysosomes Sacs containing digestive enzymes

Specialized Organelles

Only In Plant Cells: Chloroplasts (and chlorophyll) Cell Wall

Cell Wall Surrounds and

supports plant cells (and some fungi, bacteria, and algae)

Made of cellulose (most abundant biological molecule in nature)

Chloroplast Structure in which plant

cells create sugars

Contain chlorophyll (green) which captures sunlight

Sugars made in chloroplasts are used in mitochondria as energy