exam 2 (game show review)

Question 1

what types of proteins catalyze reactions in the extracellular fluid or within the cell?

Answer 1

enzymes

Question 2

besides lipid-soluble molecules, what other substances may freely cross the phospholipid bilayer?

Answer 2

oxygen

Question 3

why can oxygen easily cross through the phospholipid bilayer?

Answer 3

because it is a small, nonpolar molecule and does not interfere with the hydrogen bonds of the water

Question 4

receptor proteins, channel proteins, and recognition proteins

Answer 4

receptor proteins: receive signals from cell’s environment, like hormones
found on the cell membrane or inside the cell, ready to bind to molecules

channel proteins: form channels or pores that help facilitate transport of ions or molecules across cell
embedded in the cell membrane

recognition proteins: identify and interact with cells or molecules, especially in the context of the immune system
can be on cell surface or on membrane of organelles

Question 5

can sodium ions, glucose, or enzymes pass freely across the phospholipid bilayer?

Answer 5

no

sodium ions- small but have a positive charge, require membrane proteins (protein channels) to get through

enzymes - large complex molecules, moved by processes like vesicular transport

glucose - large polar molecule, specific transport proteins like glucose transporters take it across

Question 6

major histocompatibility complex (MHC) molecules are what type of membrane protein?

Answer 6

recognition protein

Question 7

MHC molecules (major histocompatibility complex)

Answer 7

group of genes that code for proteins found on the surfaces of cells that help the immune system recognize foreign substances

Question 8

which type of molecule is most likely to diffuse across the plasma membrane?

Answer 8

small and lipid-soluble (nonpolar)

Question 9

what concentration does osmosis go to?

Answer 9

low to high concentration (water wants to go to the hypertonic area)

Question 10

does osmosis occur across a membrane freely permeable to solutes?

Answer 10

no, only across a membrane freely permeable to water (but restricts passing of solutes)

Question 11

red blood cells create in what type of solution

Answer 11

hypertonic

Question 12

crenation vs hemolysis

Answer 12

crenation: cell shrivels up (in hypertonic solution)

hemolysis: cell swells and bursts (in hypertonic solution)

Question 13

normal saline is which type of solution?

Answer 13

isotonic

• solution of 0.9% NaCl is isotonic
• greater than 0.9% is hypertonic
• less than 0.9% is hypotonic

Question 14

which method of transport is responsible for low concentrations of sodium and high concentrations of potassium within the cells of the body?

Answer 14

active transport

Question 15

the synthesis of new organic molecules is called

Answer 15

anabolism

“anabolic avengers”
“catabolic crushers”

Question 16

a negative G value indicates that the reaction is occurring _________

Answer 16

spontaneously

Question 17

the hydrogen atoms that arrive at the electron transport system are donated by

Answer 17

NADH

Question 18

if radioactive sugar were fed to a mouse, the radioactivity would progress along which of the following paths?

Answer 18

sugar –> pyruvate –> citric acid cycle –> carbon dioxide

Question 19

which cells derive all of their ATP via glycolysis?

Answer 19

those that function in anaerobic conditions, where oxygen is limited or absent

Question 20

ertythocytes, hepatocytes, leukocytes, and neurons

Answer 20

erythrocytes: red blood cells

hepatocytes: liver cells

leukocytes: white blood cells

neurons: nerve cells

Question 21

what happens in anaerobic conditions to pyruvate?

Answer 21

pyruvate generated from glycolysis gets fermented instead

Question 22

which part of cellular respiration occurs in both aerobic and anaerobic conditions?

Answer 22

glycolysis

Question 23

does glycolysis use oxygen?

Answer 23

no, glycolysis is the process that breaks down glucose to produce ATP without the involvement of oxygen

Question 24

plants appear green to our eyes because ___________

Answer 24

photosynthetic pigments don’t absorb green light

Question 25

which of the following happens during the light-capturing reactions of photosynthesis?

Answer 25

ATP is made using light energy

Question 26

when a photon is absorbed by a pigment molecule, ___________

Answer 26

an electron in the pigment molecule is boosted (excited) to a higher energy state

Question 27

as electrons pass through the system of electron carries after leaving photosystem II, they lose energy. what happens to this energy?

Answer 27

it is used to establish and maintain a proton gradient for the generation of ATP

Question 28

what does it mean to say CO2 becomes “fixed” during photosynthesis?

Answer 28

CO2 becomes bonded to an organic molecule

• CO2 fixation in the Calvin cycle turns it into an organic compound like sugar

Question 29

2 joined copies of a replicated chromosome are called ___________

Answer 29

sister chromatids

Question 30

for most of their lives, cells are in __________ (cell cycle stage)

Answer 30

interphase

Question 31

since steroid hormones, such as estrogen and testosterone, are lipid soluble, they bind to ____________

Answer 31

receptors inside the cell

Question 32

DNA replication occurs during which phase of the cell cycle?

Answer 32

interphase

Question 33

cells get past cell-cycle checkpoints by ________________

Answer 33

cdks bound to cyclins phosphorylating other proteins