bellringer: day 01 - ms. farris' science class! · bellringer: day 01. unit 02 biochemistry,...

1. Make a list of everything you ate for dinner

last night. Categorize each item as either a

carbohydrate, fat or protein.

2. Which type of molecule (carbohydrate, fat or

protein) is the most important to your diet and

why?

Bellringer: Day 01

Unit 02Biochemistry,

Microscopes,

Eukaryotes vs.

Prokaryotes,

Cell Parts, and

Unicellular

Organisms

Cell Structure and

Function

▪ Organisms contain a number of large, organic molecules. We call these macromolecules.

▪ Some examples include:

▪ Carbohydrates

▪ Lipids

▪ Proteins

▪ Nucleic Acids

Macromolecules

▪Each of the four molecules we will discuss plays and important role in our body. For each,you are responsible for knowing:

▪Structure (building block)

▪Function (what does it do?)

Macromolecules

Carbohydrates

▪ Carbohydrates are composed of sugar molecules. They can be single, simple sugars or complex sugars. ▪ Building block:

monosaccharides▪ Function: Energy

storage

Carbohydrates

▪Glucose: The main source of energy for organisms. We will be talking about glucose in depth in later units.

▪Cellulose: Makes up cell walls of plants

▪Starch

▪Glycogen

Examples of Carbohydrates

Lipids

▪ Lipids are fatty compounds not soluble in water▪ Building block: glycerol

and three fatty acids▪ Function: Long term

energy storage, insulation, makeup the cell membrane

Lipids

▪Phospholipids: The lipids that make up the cell membrane. We will be discussing this in depth in a later unit.

▪Steroids

▪Fats/Oils

Examples of Lipids:

Nucleic Acids

▪ Nucleic acids are what make up genetic material in our bodies (DNA and RNA)▪ Building block:

nucleotides▪ Function: Storing and

transmitting genetic information

Nucleic Acids

▪DNA

▪RNA

Examples of Nucleic Acids

Proteins

▪ Proteins: Chains of amino acids; can be simple chains or complex folded structures

▪ Building block: Amino acids▪ Function: Storage, transport, movement,

structure, etc.

Proteins

▪Insulin

▪Hemoglobin

▪Enzymes: Speed up chemical reactions in your body

Examples of Proteins

1. List the four main macromolecules

we discussed yesterday. Choose 1

and describe its structure and

function.

Bellringer Day 02

ENZYMES

▪ Most enzymes are proteins

▪ Act as a catalyst to speed up a chemical reaction

by helping molecules react with each other faster

WHAT IS AN ENZYME?

▪ Reusable!

▪ Specific for what they catalyze (speed up)

▪ End in “-ase”

▪ Named for the reaction they help. For example…

▪ Sucrase breaks down sucrose

▪ Proteases break down proteins

▪ Lipases break down lipids

▪ DNA polymerase builds DNA

ENZYMES ARE…

▪ Lactase breaks down lactose, a common component of dairy products (like milk)

▪ People lacking the enzyme lactase are considered “lactose intolerant”-they can’t digest large amounts of milk!!

CASE STUDY: LACTOSE INTOLERANCE

▪ Re-used again for the same reaction with other molecules

▪ Very little enzyme is needed to help in many reactions!

ENZYMES ARE NOT USED UP!

Products

Substrate

Active

Site

Enzyme

▪ Remember, enzymes are

specific!

▪ Lock and Key Model: Shape of

enzyme allows substrate to fit

▪ Specific enzyme for each

specific reaction

LOCK AND KEY MODEL

Chemical Reaction

Enzyme + Substrate → Enzyme + Product

REACTANTS PRODUCTS

▪ Enzymes work by weakening bonds, which lowers

ACTIVATION ENERGY

▪ Activation Energy=energy needed for the chemical

reaction to occur (energy needed to activate!)

▪ By lowering the activation energy, the reaction can

occur faster!

SO…HOW DO ENZYMES WORK?

Reactions can occur without

the help…but not at the

speed our bodies need!

▪ Temperature

▪ High temperatures can cause enzymes to denature (unfold and lose shape), while low temperatures slow molecules down

▪ pH

▪ Changes in pH changes protein shape (most human proteins sit at a pH of 6-8)

▪ Denaturing=extreme temperature and pH can change enzyme shape, rendering it useless!

WHAT EFFECTS ENZYME ACTIVITY?

▪ Every reaction in your body is helped by an

enzyme. They are necessary for all biological

reactions!

WHY ARE ENZYMES IMPORTANT?

1. The location where reactants bind to an enzyme during a

biochemical reaction is called

a) A catalyst

b) A product

c) A substrate

d) An active site

2. How do enzymes speed up biochemical reactions?

a) They provide energy to the reactants

b) They absorb energy from the products

c) They lower the activation energy of the reaction

d) They increase the number of available reactant particles

Light Microscopes and Total Power Magnification

We can use microscopes to observe cells in greater detail Light microscopes are what we will use in class More advanced microscopes, like scanning and electron

transmission microscopes, allow us to see prokaryotic and eukaryotic cell differences in greater detail

Think about it: How does an electron microscope work? Why are these microscopes so expensive?

-A beam of electrons is scanned over a surface to create an image. They are larger, and more expensive to build and maintain!

To find this, multiply the power of the objective lens (4X, 10X, 40X), by the power of the eyepiece (usually 10X)

Think about it: A student is viewing a slide using an objective lens with a power of 4X. What is the total power magnification?

4 x 10 = 40X

Structure and Function of Living Organisms

A cell is the basic structural, functional, and biological unit of all living organisms

▪ “The building block of life”

You are made up of about 37 trillion cells!!!]

Think about it: How do a human and an elephant differ?

▪ The elephant has more cells because it is larger, but the cells themselves are not bigger!

What do we know about cells?

▪ In 1665, Robert Hooke used an early microscope to look at a thin slice of cork, a plant material.

▪ Cork looked like thousands of tiny, empty chambers.

▪ Hooke called these chambers “cells.”

▪ In 1838, Matthias Schleiden concluded that all plants were made of cells.

▪ In 1839, Theodor Schwann stated that all animals were made of cells.

▪ In 1855, Rudolph Virchow concluded that new cells were created only from division of existing cells.

▪ These discoveries led to the cell theory.

1. All living things are composed of cells. 2. Cells are the basic units of structure and

function in living things. 3. New cells are produced from existing cells.

1. What is a cell? What does cell theory tell us about cells?

2. A student is viewing a microscope with an objective lens of 40x. What is the total power magnification?

1. Are all cells the same? Why or why not?Support your answer.

Prokaryotic

▪ Simple Cells

Eukaryotic

▪ Complex Cells

▪ Plant and Animal Cells

Prokaryotic cells are smaller and less complex than eukaryotic cells▪ No membrane bound

organelles; smaller Single-celled organisms

(ex. Bacteria) Contains: Single, circular

DNA; ribosomes; cell membrane

Eukaryotic cells are larger, complex cells made up of membrane bound organelles

Each organelle within the cell carries out different roles

Eukaryotic cells make up complex organisms (mostly multicellular)…like insects, fish, and mammals like you!

PROKARYOTIC

No membrane bound organelles (no mitochondria, nucleus, vacuole, or chloroplasts)

Ribosomes One strand of circular DNA

not enclosed in a nucleus Additional circular DNA

(plasmids) can be present Smaller size

EUKARYOTIC

Contains membrane bound organelles

Ribosomes DNA (enclosed by

membrane) DNA double-helix strands Larger size

Compare and contrast prokaryotic and eukaryotic cells.

Animal vs. Plant

Animal Cell

•Nucleus•Plasma Membrane•Mitochondria•Vacuoles•Ribosome•Cytoplasm•Lysosome

Plant Cell

•Nucleus•Plasma Membrane•Mitochondria•Ribosome•Cytoplasm•Vacuole (large)•Chloroplasts•Cell Wall

The “control center” Holds the DNA Dark spot inside

nucleus is called the nucleolus (it helps makes the ribosomes)

Nucleus

The “powerhouse” of the cell

It produces most of the energy for the cell

Breaks down food to make ATP▪ ATP is major fuel for all cell

activities that require energy

Folded inner membrane increase the surface area for energy production during respiration

Mitochondria

Think about it: Which cells would need a lot of mitochondria?

Think about it: What would happen if the cell lost all of its mitochondria?

The “gate” of the cell Double membrane

structure controls what comes in and out of the cell

“YOU SHALL NOT PASS” (without permission!)

Plasma Membrane

Protein producer The ribosome makes

proteins for the cell Can be attached to

the ER or free floating in the cytoplasm

Ribosome

“Storage tanks” of the cell

It stores food, water, and chemicals in the cell

Plant cell vacuole is much larger; controls Turgor Pressure-keeps plant upright (no water=wilting)

Vacuole

Jelly/gel A liquid/gel like

substance that surrounds the organelles

Cytoplasm

The “garbage cans” Break down and digest

waste products using enzymes

Lysosome

Think about it: what would happen to the cell if all of the lysosomes burst at the same time? Does this every happen on purpose?

“Supporter/protector” The cell wall shapes

and protects the plant cell

Cell Wall

Think about it: What is the plant cell made of? (Hint: What substance do plants make during photosynthesis?)

Food producers They are green Contain green chlorophyll

and trap energy from the sun for photosynthesis

Glucose (sugar) producers Produce enough ATP to

fuel photosynthesis

Chloroplast

All these organelles work together to keep the cell running!!

Think about it: What do you think would happen if…

▪ The Mitochondria or Chloroplasts stopped working?

▪ The Plasma Membrane didn’t do its job?

▪ The Nucleus stopped directing activities?

1. How are prokaryotic and eukaryotic cells similar?a) Both contain a nucleus

b) Both contain ribosomes

c) Both contain membrane-bound organelles

d) Both contain cell walls2. This diagram shows a plant cell. Which structure is

found in a plant cell but absent in an animal cell?a) 1

b) 2

c) 3

d) 4

Found only in plant cells, this organelle converts radiant energy to chemical energy through the process of photosynthesis.

This organelle is significantly larger in plant cells in order to aid in keeping plants upright. If this organelle is not full, the plant will wilt.

The folded inner membranes of this organelle provide more surface area for increased ATP production.

These small organelles are vital for the production of proteins in a cell.

This organelle controls cell functions and houses DNA.

This organelles unique structure allows for the selective passage of molecules into and out of the cell.

Nucleus▪ “Brain of the cell”-controls cell functions and

stores DNA Mitochondria

▪ “Powerhouse of the cell”-makes energy through cellular respiration; folded inner membrane provides lots of surface area for cell processes

Cell membrane▪ “Gate of the cell”-Double membrane structure

composed of lipids-controls what goes in and out

Ribosomes

▪ Site of protein synthesis (makes proteins); attached or free floating

Cytoplasm

▪ Jelly/gel that surrounds cells-keeps organelles where they should be

Vacuole

▪ “Storage center”-holds water, food, etc.-large in plants due to Turgor Pressure

Chloroplast

▪ Plants only-uses sunlight to convert to sugar through process of photosynthesis

Cell wall

▪ Plants only-carbohydrate called cellulose provides rigid structure that protects and supports cell

Lysosome

▪ “Garbage can”-animals only. Uses enzymes to digest waste products

Endoplasmic Reticulum-Network of membranes that fold, modify, and transports proteins throughout the cell

Golgi Apparatus-receives proteins and lipids (fats); modifies, sorts, and packs them; works closely with the ER

Cells all begin as undifferentiated

Undifferentiated=not different; the same

DNA determines the type of cell (ex. nerve cell, muscle, blood…)

We will talk more about this later!

Mitochondria? Why? Chloroplasts? Why?

Cell organelles can be more concentrated based on needs!

http://www.glencoe.com/sites/common_assets/science/virtual_labs/E08/E08.html

▪ Interactive cell where you match organelle to name and function

https://quizlet.com/3082892/cell-organelles-review-flash-cards/

▪ Quizlet with flashcards, games, and quizzes

Decide whether the cell is plant or animal. Next, label the parts with the appropriate name.

Structure and Adaptations

A “multicellular” organism is composed of many cells (ex. You are composed of many animal cells; plants are composed of many plant cells)

“Unicellular” means they are composed of a single cell!

▪ Ex. Bacteria, protozoa, euglena

Unicellular organisms have many structures that help them survive

▪ Contractile vacuoles

▪ Cilia

▪ Flagella

▪ Pseudopods

▪ Eyespots

Stores excess water that enters the cell, and expels it to the exterior

▪ It expands when filling with water, then contracts, expelling the contents back out

▪ Found in: protists + unicellular algae

https://www.youtube.com/watch?v=pahUt0RCKYc

A dark area that functions in light reception; influences motion so that the organism can move toward/ away from light▪ Toward (positive phototaxis)

▪ Away (negative phototaxis)

▪ Found in: green algae; photosynthetic unicellular organisms

Cilia▪ Many hair like structures▪ Often used for movement▪ Non-motile cilia serve as

sensory organelles

Flagella▪ Single, whip like tail used

for movement▪ Found in: bacteria,

protists, specialized plant, animal and fungi cells

https://www.youtube.com/watch?v=QGAm6hMysTA

Pseudopods

▪ “False feet” that help the unicellular organism move about

▪ Sometimes used to obtain food (phagocytosis)

https://www.youtube.com/watch?v=PsYpngBG394

Recall that “taxis” is an innate behavior in response to an outside stimuli

Movement in response to chemicals (“chemo”). Some single celled organisms direct their

movement according to chemicals in their environment

Found in bacteria and single-cell or multicellular organisms

▪ Find food (e.g., glucose)

▪ Flee from poisons (e.g., phenol)

▪ Critical to early development

Movement toward or away from light. Many plant-like unicellular organisms will

move toward light to better photosynthesize, just like plants will tilt toward the window

▪ Positive phototaxis: if the movement is in the direction of increasing light intensity

▪ Negative phototaxis: if the movement is in the opposite direction of light intensity

https://www.youtube.com/watch?v=2koAGkgmiqg

Challenge: Identify the following cells:

Take a few minutes to study!