Review 1

Question 1

What is an element

Answer 1

Each element is designated by its chemical
symbol (such as H, N, O, C, and Na), and
possesses unique properties.
-he number for each element is the atomic
number referring to the number of protons in
the nuclei of atoms
- Elements are comprised of atoms

Question 2

What is an atom

Answer 2

Atoms are made of protons and neutrons located
within the nucleus, and electrons surrounding the
nucleus
* Atomic number (number of protons) for each
element is different
An atom is the smallest component of an
element that retains all of the chemical
properties of that element.

Question 3

What is a macromolecule

Answer 3

Many critical nutrients come as
macromolecules
* macromolecules are built from different
combinations of smaller organic molecules

Question 4

what is water

Answer 4

Water is cohesive: molecules form strong
bonds with each other
* Life’s most important molecule, and necessary
for life
* Small traces of it on another planet can indicate
that life could or did exist on that planet
* one of the most abundant molecules in living
cells
* Approximately 60–70% of your body is water

Question 5

what is a biological macromolecule

Answer 5

large molecules
needed for life that are built from smaller
molecules
* Four major classes of biological macromolecules:
carbohydrates, lipids, proteins, and nucleic acids
* each is an important component of the cell and
performs a wide array of functions
* Combined, these molecules make up the majority
of a cell’s mass

Question 6

What is carbon

Answer 6

Carbon can form:
* large branching chains with
other C
* Rings with other C
* Bonds with other elements (e.g.
N, O), which in turn form chains
and rings

Question 7

what are the four classes of biological macromolectules

Answer 7

• Carbohydrates
• Lipids
• Proteins
• Nucleic Acids
• All made using carbon combined with other
  elements

Question 8

what are the types of carbohydrates

Answer 8

glucose
* Starch
* Glycogen
* Cellulose
* Chitin

Question 9

what is glucose

Answer 9

glucose is the source of energy for cells

Question 10

what is starch

Answer 10

Starch is the stored form of sugars in plants, and
is broken down into glucose

Question 11

what is glycogen

Answer 11

Glycogen is the stored form of sugars in animals,
and is released into the bloodstream when
glucose levels are low

Question 12

what is cellulose

Answer 12

Cellulose comprises the cell walls of plants, and
adds structural support to the cells

Question 13

what is chitin

Answer 13

Chitin forms the exoskeleton of insects and crabs,
which works to protect their internal body parts

Question 14

what is lipid

Answer 14

A group of compounds that do not dissolve in
water – they are non-polar
* provide insulation from the environment for
plants and animals
* E.g. help keep ducks dry because resist water
Cells store energy for long-term use as fats
* building blocks of many hormones
* an important part of the plasma membrane in
cells

Question 15

what is protein

Answer 15

• abundant macromolecules with diverse functions
• E.g. animo acids
• Each cell in a living system may contain
  thousands of different proteins, each with a
  unique function.
• Functions:
• Transport, storage, membranes, or structure for
  living things

Question 16

what are the types of proteins

Answer 16

enzymes and hormones

Question 17

what is enzymes

Answer 17

produced by living cells, are catalysts
in biochemical reactions (like digestion) and
break down molecular bonds
* E.g. salivary amylase breaks down starch

Question 18

what is hormones

Answer 18

chemical signaling molecules that act
to control specific physiological processes, like
growth, development, metabolism, and
reproduction.
* E.g. insulin is a protein hormone that maintains
blood glucose levels

Question 19

what is amino acids

Answer 19

Are the macromolecule
building blocks that make up
all proteins
* There are 20 different animo
acids, and their structure in
one area of the molecule is
the only difference
* E.g. valine

Question 20

what is nucleic acids

Answer 20

Macromolecules that carry the genetic
blueprint of a cell
* carry instructions for the functioning of the
cell
* Two main types: DNA and RNA

Question 21

what is DNA

Answer 21

deoxyribonucleic acid (DNA)
* DNA is the genetic material found in all living
organisms, ranging from single-celled bacteria
to multicellular mammals.
* DNA molecules never leave the nucleus, but
instead use an RNA intermediary to
communicate with the rest of the cell

Question 22

what is RNA

Answer 22

ribonucleic acid (RNA)
* mostly involved in protein synthesis
* Sent by DNA to communicate with the rest of
the cell
* involved in protein synthesis and its regulation

Question 23

what is the cell

Answer 23

The smallest unit of a living thing
* The building blocks of all organisms
* In multicellular organisms, cells of the same
kind connect together
* They perform shared functions to form tissues
e.g. muscle tissue
* several tissues combine to form an organ (e.g.
brain)

Question 24

what is the meaning of eukaryotic

Answer 24

animal, plant, fungal, protist cells

Question 25

what is the meaning of prokaryotic

Answer 25

some bacteria and archaea cells

Question 26

what is the unified cell theory

Answer 26

1) all living things are composed of one or
more cells
* 2) the cell is the basic unit of life
* 3) all new cells arise from existing cells

Question 27

what are the characteristics of all cells

Answer 27

• All cells share four common components:
• 1) a plasma membrane (outer covering that
  separates the cell’s interior from the surrounding
  environment
• 2) cytoplasm (a jelly-like region within the cell
  where other cellular components are found)
• 3) DNA (genetic material of the cell)
• 4) ribosomes (particles that make proteins)

Question 28

what is the cytoplasm:

Answer 28

jelly-like substance that makes up
the contents of a cell between the plasma
membrane and nucleus

Question 29

what is the cytoskeleton?

Answer 29

a network of protein
fibers in a cell’s cytoplams that helps
to maintain the shape of the cell

Question 30

what is the flagella

Answer 30

long, hair-like
structures that extend from the plasma
membrane and are used to move a cell

Question 31

what is cilia

Answer 31

short, hair-like
structures used to move cells or substances
along the outer cell membrane

Question 32

what is ribosomes

Answer 32

enzyme complexes in the cell
responsible for protein synthesis.

Question 33

what is the nucleus

Answer 33

the cell’s “brain”

Question 34

what is chromosomes

Answer 34

structures within the nucleus
that are made up of DNA (hereditary material)
and proteins.

Question 35

what is chromatin

Answer 35

DNA and proteins when not
distinguishable as chromosomes

Question 36

what is the nucleolus

Answer 36

the part of the nucleus that directs
the synthesis of ribosomes

Question 37

what is the endplasmic reticulum

Answer 37

On the outside of nucleus
* Membrane of ER is
continuous with nuclear
envelope
* a series of interconnected
membranous tubules that
modify proteins and
synthesize lipids

Rough ER: has ribosomes attached

Smooth ER: has few/no ribosomes on surface
* Is continuous with RER and part of nuclear
envelope

Question 38

what is the golgi body

Answer 38

Sorts, tags, and distributes lipids and proteins
* A series of flattened membranous sacs in
cytoplasm
* Vesicles containing proteins/lipids that bud
from the ER go to golgi bodies
* Before reaching their final destination, the
lipids or proteins within the transport vesicles
need to be sorted, packaged, and tagged so
that they wind up in the right place
Tag proteins/lipids by adding a short chain of
sugar molecules that allow them to be routed
to proper destination in cell
* Usually many golgi bodies in cell, although
cells that secrete many molecules (e.g.
digestive cells that secrete enzymes) have
more than others

Question 39

what is lysosomes

Answer 39

The “garbage disposal” in animal cells
* Contain digestive enzymes that aid the
breakdown of proteins, polysaccharides,
lipids, nucleic acids, worn-out organelles, and
disease-causing organisms
* In single-celled eukaryotes, lysosomes help
with food digestion and organelle recycling
Lysosome enzymes are active at a much lower
pH (more acidic) than those located in the
cytoplasm
* Many reactions that take place in the
cytoplasm could not occur at a low pH, thus
the advantage of compartmentalizing the
eukaryotic cell into organelles is apparen

Question 40

what is phagocytosis

Answer 40

a section of the plasma membrane
folds in and engulfs a pathogen

Question 41

what is vesticles and vacuoles

Answer 41

Vesicles and vacuoles are membrane-bound
sacs that function in storage and transport.
* Vacuoles: larger than vesicles; membrane
does not fuse with the membranes of other
cellular components
* Plant vacuole enzymes can break down
macromolecules
* Vesicles: smaller; membrane can fuse with
other membranes within the cell

Question 42

what is the mitochondrial

Answer 42

powerhouses” of cell
* responsible for making adenosine triphosphate
(ATP), the cell’s main energy carrying molecule
* The formation of ATP from the breakdown of
glucose is known as cellular respiration
* Mitochondria are oval-shaped, double-membrane
organelles in cytoplasm
* Each membrane is phospholipid bilayer embedded
with proteins
* Also have their own ribosomes and DNA
* Muscles cells have many mitochonria, because need
lots of energy to contract